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NAME:_____________________________
TUTOR GROUP:______________________
Knowledge Organiser
MATHEMATICS GCSE Mathematics AQA
MA
THEM
ATI
CS
GC
SE M
ath
em
atic
s A
QA
YEAR 11
(Autumn) 2021-2023
Topic 11 1.1 Polygons and Circles
Topic/Skill Definition/Tips Example Your turn
1 Types of Angles
Acute angles are less than 90Β°.
Right angles are exactly 90Β°.
Obtuse angles are greater than 90Β° but less than
180Β°.
Reflex angles are greater than 180Β° but less than
360Β°.
What type of angle is this?
Measure the angle.
2 Angle Notation Can use one lower-case letters, e.g. π or π₯
Can use three upper-case letters, e.g. π΅π΄πΆ.
Write the angle x using three upper case
letters.
3 Angles at a Point Angles around a point add up to 360Β°.
Work out the size of angle x.
4 Angles on a
Straight Line Angles on a straight line add up to 180Β°.
Work out the size of angle x.
5 Opposite Angles Vertically opposite angles are equal.
Work out the size of angle x and y..
Give reasons for your answers
Work out the size of angle FGD.
Give reasons for your answer.
6 Alternate Angles
Alternate angles are equal.
They look like Z angles, but never say this in the
exam.
7 Corresponding
Angles
Corresponding angles are equal.
They look like F angles, but never say this in the
exam.
8 Co-Interior Angles
Co-Interior angles add up to 180Β°.
They look like C angles, but never say this in the
exam.
9 Angles in a
Triangle Angles in a triangle add up to 180Β°.
Work out the size of the missing angle.
10 Types of Triangles
Right Angle: Triangles that have a 90Β° angle.
Isosceles: Triangles that have 2 equal sides and 2
equal base angles.
Equilateral: Triangles that have 3 equal sides and
3 equal angles (60Β°).
Scalene: Triangles that have different sides and
different angles.
Base angles in an isosceles triangle are equal.
Work out the size of angle x.
11 Angles in a
Quadrilateral Angles in a quadrilateral add up to 360Β°.
Find x.
12 Polygon A 2D shape with only straight edges. Rectangle, Hexagon, Decagon, Kite etc.
13 Regular A shape is regular if all the sides and all the angles
are equal.
14 Names of
Polygons
3-sided = Triangle.
4-sided = Quadrilateral.
5-sided = Pentagon.
6-sided = Hexagon.
7-sided = Heptagon/Septagon.
8-sided = Octagon.
9-sided = Nonagon.
10-sided = Decagon.
15 Interior and
Exterior Angles
Interior angle + exterior angle = 180Β°.
Sum of Exterior Angles = 360Β°.
16 Sum of Interior
Angles
(π β π) Γ πππ
Where n is the number of sides.
Sum of Interior Angles in a Heptagon = (7 β 2) Γ 180 = 900Β°
96 + 105 + 161+ 123 + 155 + 114= 754
900 β 754 = 146
π₯ = 146
Work out the sum of the interiors angle in
pentagon.
Work out x.
17 Size of Interior
Angle in a Regular
Polygon
(π β π) Γ πππ
π
You can also use the formula: πππ β πΊπππ ππ π¬πππππππ π¨ππππ
Size of Interior Angle in a Regular Pentagon = (5 β 2) Γ 180
5= 108Β°
Work out the size of each interior angle in a
regular octagon.
18 Size of Exterior
Angle in a Regular
Polygon
πππ
π
You can also use the formula: πππ β πΊπππ ππ π°πππππππ π¨ππππ
Size of Exterior Angle in a Regular Octagon = 360
8= 45Β°
Work out the size of each exterior angle in a
regular hexagon.
19
H Circle Theorem 1
Angles in a semi-circle have a right angle at the
circumference.
π¦ = 90Β° π₯ = 180 β 90 β 38 = 52Β°
Find x.
20
H Circle Theorem 2
Opposite angles in a cyclic quadrilateral add up
to 180Β°.
π₯ = 180 β 83 = 97Β° π¦ = 180 β 92 = 88Β°
Find x and y.
21
H Circle Theorem 3
The angle at the centre is twice the angle at the
circumference.
π₯ = 104 Γ· 2 = 52Β° Find x.
22
H Circle Theorem 4
Angles in the same segment are equal. π₯ = 42Β° π¦ = 31Β°
Find x and y .
23 Tangent
A straight line that touches a circle at exactly one
point, never entering the circleβs interior.
A radius is perpendicular to a tangent at the
point of contact.
Topic 11 1.2 Statistics 2
Topic/Skill Definition/Tips Example Your turn
1 Mean from a Table
1) Find the midpoints (if necessary).
2) Multiply Frequency by values or midpoints.
3) Add up these values.
4) Divide this total by the Total Frequency.
If grouped data is used, the answer will be an
estimate.
Estimated mean height: 450 Γ· 24 = 18.75.
Calculate an estimate for the mean.
2 Median from a
Table
Use the formula (π+π)
π to find the position of the
median.
π is the total frequency.
The total frequency is 24, the median will be
the (24+1
2) = 12.5π‘β position.
The interval containing the median is 10 < β β€
30.
Which interval contains the median in the table
above?
3 Line Graph
A graph that uses points connected by straight
lines to show how data changes in values.
This can be used for time series data, which is a
series of data points spaced over uniform time
intervals in time order.
4
H
Histograms
A visual way to display frequency data using bars.
Bars can be unequal in width.
Histograms show frequency density on the y-axis,
not frequency.
πππππππππ π«ππππππ = πππππππππ
πͺππππ πΎππ ππ
Draw a histogram
5
H
Interpreting
Histograms
The area of the bar is proportional to the
frequency of that class interval.
πππππππππ = ππππ π«ππππππ Γ πͺππππ πΎππ ππ
A histogram shows information about the
heights of a number of plants. 4 plants were
less than 5cm tall. Find the number of plants
more than 5cm tall.
Above 5cm:
1.2 x 10 + 2.4 x 15 = 12 + 36 = 48
30 pigs weigh between 50 and 65 kg.
Work out an estimate for the number of pigs
which weigh more than 80kg.
Topic 11 1.3 Algebra
Topic/Skill Definition/Tips Example Your turn
1 Rearranging
Formulae
Use inverse operations on both sides of the
formula (balancing method) until you find the
expression for the letter.
Make x the subject of π¦ =2π₯β1
π§
Multiply both sides by z π¦π§ = 2π₯ β 1
Add 1 to both sides π¦π§ + 1 = 2π₯
Divide by 2 on both sides π¦π§ + 1
2= π₯
We now have x as the subject.
Make t the subject of the formula. π’ = 4π‘ β 21
2 Simultaneous
Equations
A set of two or more equations, each involving
two or more variables (letters).
The solutions to simultaneous equations satisfy
both/all of the equations.
2π₯ + π¦ = 7 3π₯ β π¦ = 8 5π₯ = 15
π₯ = 3
Now substitute this value of x into one of the
equations. 2 Γ 3 + π¦ = 7
π¦ = 1
Solve: 6π₯ + π¦ = 18 4π₯ + π¦ = 14
3 Variable A symbol, usually a letter, which represents a
number which is usually unknown. In the equation π₯ + 2 = 5, π₯ is the variable.
4 Coefficient
A number used to multiply a variable.
It is the number that comes before/in front of a
letter.
6z.
6 is the coefficient.
z is the variable.
+ + Γ· 5 Γ· 5
5
Solving
Simultaneous
Equations (by
Elimination)
1) Balance the coefficients of one of the variables.
2) Eliminate this variable by adding or subtracting
the equations (Same Sign Subtract, Different Sign
Add).
3) Solve the linear equation you get using the other
variable.
4) Substitute the value you found back into one of
the previous equations.
5) Solve the equation you get.
6) Check that the two values you get satisfy both of
the original equations.
5π₯ + 2π¦ = 9 10π₯ + 3π¦ = 16
Multiply the first equation by 2.
10π₯ + 4π¦ = 18 10π₯ + 3π¦ = 16
Same Sign Subtract (+10x on both) π¦ = 2
Substitute π¦ = 2 into equation.
5π₯ + 2 Γ 2 = 9
5π₯ + 4 = 9 5π₯ = 5 π₯ = 1
Solution: π₯ = 1, π¦ = 2
Solve: 4π₯ + 9π¦ = 10 2π₯ + 3π¦ = 2
6
Solving
Simultaneous
Equations (by
Substitution)
1) Rearrange one of the equations into the form
π¦ = β― or π₯ = β―.
2) Substitute the right-hand side of the rearranged
equation into the other equation.
3) Expand and solve this equation.
4) Substitute the value into the π¦ = β― or π₯ = β―
equation.
5) Check that the two values you get satisfy both
of the original equations.
π¦ β 2π₯ = 3 3π₯ + 4π¦ = 1
Rearrange: π¦ β 2π₯ = 3 β π¦ = 2π₯ + 3
Substitute: 3π₯ + 4(2π₯ + 3) = 1
Solve: 3π₯ + 8π₯ + 12 = 1 11π₯ = β11
π₯ = β1
Substitute: π¦ = 2 Γ β1 + 3 π¦ = 1
Solution: π₯ = β1, π¦ = 1
Solve: π₯ = 10 β π¦
2π₯ + π¦ = 17
7
Solving
Simultaneous
Equations
(Graphically)
Draw the graphs of the two equations.
The solutions will be where the lines meet.
The solution can be written as a coordinate.
Solve 2π₯ β 1 = 5 β π₯
π¦ = 5 β π₯ and π¦ = 2π₯ β 1.
They meet at the point with coordinates (2,3)
so the answer is:
π₯ = 2 and π¦ = 3
Use the graph to solve π₯2 β π₯ + 1 = 7
We draw the line y = 7 on our graph and look
at where it crosses the curve.
The lines meet at the points with coordinates
(-2,7) and (3,7), so the answers are:
π₯ = β2, π¦ = 7 and π₯ = 3, π¦ = 7
a) Use the graph to solve βπ₯ + 4 = π₯ β 2
b) Use the graph to solve 2π₯2 β 5π₯ + 1 = 1
8
H
Solving Linear and
Quadratic
Simultaneous
Equations
Method 1: If both equations are in the same form
(e.g. Both π¦ =β¦):
1) Set the equations equal to each other.
2) Rearrange to make the equation equal to zero.
3) Solve the quadratic equation.
4) Substitute the values back in to one of the
equations.
Method 2: If the equations are not in the same
form:
1) Rearrange the linear equation into the form π¦ =
β― or π₯ = β―
2) Substitute into the quadratic equation.
3) Rearrange to make the equation equal to zero.
4) Solve the quadratic equation.
5) Substitute the values back in to one of the
equations.
You should get two pairs of solutions (two values
for π₯, two values for π¦).
Graphically, you should have two points of
intersection.
Example 1
Solve :
π¦ = π₯2 β 2π₯ β 5 and π¦ = π₯ β 1
π₯2 β 2π₯ β 5 = π₯ β 1 π₯2 β 3π₯ β 4 = 0
(π₯ β 4)(π₯ + 1) = 0
π₯ = 4 and π₯ = β1
π¦ = 4 β 1 = 3 and π¦ = β1 β 1 = β2
Answers: (4,3) and (-1,-2)
Example 2
Solve:
π₯2 + π¦2 = 5 and π₯ + π¦ = 3
π₯ = 3 β π¦
(3 β π¦)2 + π¦2 = 5 9 β 6π¦ + π¦2 + π¦2 = 5
2π¦2 β 6π¦ + 4 = 0 π¦2 β 3π¦ + 2 = 0
(π¦ β 1)(π¦ β 2) = 0
π¦ = 1 and π¦ = 2
π₯ = 3 β 1 = 2 and π₯ = 3 β 2 = 1
Answers: (2,1) and (1,2)
Solve: π¦ = π₯ + 3
π¦ = π₯2 + 5π₯ β 2
9
H
Completing the
Square (when π =1)
A quadratic in the form π₯2 + ππ₯ + π can be written
in the form (π + π)π + π.
1) Write a set of brackets with π₯ in and half the
value of π.
2) Square the bracket.
3) Subtract (π
2)
2and add π.
4) Simplify the expression.
You can use the completing the square form to
help find the maximum or minimum of quadratic
graph.
Complete the square of :
π¦ = π₯2 β 6π₯ + 2
Answer:
(π₯ β 3)2 β 32 + 2 = (π₯ β 3)2 β 7
The minimum value of this expression occurs
when (π₯ β 3)2 = 0, which occurs when π₯ = 3
When π₯ = 3, π¦ = 0 β 7 = β7.
Minimum point = (3, β7)
Complete the square and find the minimum
value of:
π₯2 + 8π₯ + 1
10
H
Completing the
Square (when π β 1)
A quadratic in the form ππ₯2 + ππ₯ + π can be written
in the form p(π + π)π + π.
Use the same method as above but factorise out π
at the start.
When a question asks for the answer in the form
(π₯ + π)2 + π you need to complete the square.
Complete the square of:
4π₯2 + 8π₯ β 3
Answer:
4[π₯2 + 2π₯] β 3 = 4[(π₯ + 1)2 β 12] β 3
= 4(π₯ + 1)2 β 4 β 3 = 4(π₯ + 1)2 β 7
Complete the square of:
2π₯2 + 8π₯ + 2
11
H
Solving Quadratics
by Completing the
Square
Complete the square in the usual way and use
inverse operations to solve.
Solve:
π₯2 + 8π₯ + 1 = 0
Answer: (π₯ + 4)2 β 42 + 1 = 0
(π₯ + 4)2 β 15 = 0 (π₯ + 4)2 = 15
(π₯ + 4) = Β±β15
π₯ = β4 Β± β15
Solve by completing the square:
π₯2 β 8π₯ + 3 = 0
2π₯2 β 12π₯ + 7 = 0
12
H
Turning Point of a
Quadratic
A turning point is the point where a quadratic
turns.
When the equation of the curve is in the form:
π = π(π + π)π + π
or π = βπ(π + π)π + π
the turning point is (βπ, π).
Find the turning points of:
π₯2 + 6π₯ + 1 = 0
Complete the square. (π₯ β 3)2 β 8 = 0
So the turning point is (3,-8)
Find the turning points of:
π₯2 β 4π₯ + 3 = 0
Maximum Minimum
13
H
Quadratic
Inequalities
Sketch the quadratic graph of the inequality.
If the expression is > ππ β₯ then the answer will be
above the x-axis.
If the expression is < ππ β€ then the answer will be
below the x-axis.
Look carefully at the inequality symbol in the
question.
Look carefully if the quadratic is a positive or
negative parabola.
Solve the inequality π₯2 β π₯ β 12 < 0
Sketch the quadratic:
The required region is below the x-axis, so the
final answer is: β3 < π₯ < 4
If the question had been > 0, the answer
would have been: π₯ < β3 ππ π₯ > 4
Solve the inequality:
π₯2 β 3π₯ β 10 β€ 0
Write the solution using set notation.
14 Set Notation
A set is a collection of things, usually numbers,
denoted with brackets { }.
{π₯ | π₯ β₯ 7} means βthe set of all xβs, such that x is
greater than or equal to 7β.
Some people use β:β instead of β|β
The βxβ can be replaced by any letter.
{3, 6, 9} is a set.
{π₯ βΆ β3 β€ π₯ < 4}
15
Function notation
π(π₯)
π is the input value
π(π) is the output value.
π(π₯) = 3π₯ + 11
Suppose the input value is π₯ = 5.
The output value is π(5) = 3 Γ 5 + 11 = 26
π(π₯) = 2π₯ β 5
Find:
a) π(3) =
b) π(β1) =
16
H Inverse function
πβ1(π₯)
A function that performs the opposite process of
the original function.
1) Write the function as π¦ = π(π₯)
2) Rearrange to make π₯ the subject.
3) Replace the π with π and the π with πβπ(π)
π(π₯) = (1 β 2π₯)5. Find the inverse function.
π¦ = (1 β 2π₯)5
βπ¦5 = 1 β 2π₯
1 β βπ¦5 = 2π₯
1 β βπ¦5
2= π₯
πβ1(π₯) =1 β βπ₯
5
2
π(π₯) = (π₯ + 3)3
Find πβ1(π₯)
17
H
Composite
function
A combination of two or more functions to create
a new function.
ππ(π) is the composite function that substitutes
the function π(π) into the function π(π).
ππ(π) means βdo g first, then fβ.
ππ(π) means βdo f first, then gβ.
π(π₯) = 5π₯ β 3 π(π₯) =1
2π₯ + 1
What is ππ(4)?
π(4) =1
2Γ 4 + 1 = 3
π(3) = 5 Γ 3 β 3 = 12 = ππ(4)
What is ππ(π₯)?
ππ(π₯) = 5 (1
2π₯ + 1) β 3 =
5
2π₯ + 2
π(π₯) = 2π₯ + 3, π(π₯) = π₯2
Find ππ(π₯)
Find ππ(π₯)
18
H
Equation of a
Circle
The equation of a circle, centre (0,0), radius r, is:
π₯2 + π¦2 = π2
π₯2 + π¦2 = 25
Centre (0,0) radius 5. What is the centre and radius of a circle with
equation:
π₯2 + π¦2 = 49
Write the equation of a circle with the centre
(0,0) and radius 4:
Topic 11 1.4 Congruence and Similarity
Topic/Skill Definition/Tips Example Your turn
1 Congruent Shapes
Shapes are congruent if they are identical - same
shape and same size.
Shapes can be rotated or reflected but still be
congruent.
These are all congruent to each other. Are these shapes congruent?
a)
b)
2 Congruent
Triangles
4 ways of proving that two triangles are congruent:
1) SSS (Side, Side, Side)
2) RHS (Right angle, Hypotenuse, Side)
3) SAS (Side, Angle, Side)
4) ASA (Angle, Side, Angle) or AAS
ASS does not prove congruency.
π΅πΆ = π·πΉ ( = 8ππ)
π΄π΅πΆ = πΈπ·πΉ ( = 73Β°) π΄πΆπ΅ = πΈπΉπ· ( = 61Β°)
So, the triangles are congruent by ASA.
Show these two triangles are congruent:
3 Similar Shapes
Shapes are similar if they are the same shape but
different sizes.
The proportion of the matching sides must be the
same, meaning the ratios of corresponding sides
are all equal.
These shapes are all similar. The two on the
right are congruent to each other, but not to
the one on the left.
4 Scale Factor
The ratio of corresponding sides of two similar
shapes.
To find a scale factor, divide a length on one
shape by the corresponding length on a similar
shape.
Scale Factor = 15 Γ· 10 = 1.5
5 Finding missing
lengths in similar
shapes
1) Find the scale factor.
2) Multiply or divide the corresponding side to
find a missing length.
If you are finding a missing length on the larger
shape you will need to multiply by the scale factor.
If you are finding a missing length on the smaller
shape you will need to divide by the scale factor.
Scale Factor = 3 Γ· 2 = 1.5 π₯ = 4.5 Γ 1.5 = 6.75ππ
Find the missing length.
6 Similar Triangles
To show that two triangles are similar, show that:
1) The three sides are in the same proportion.
2) Two sides are in the same proportion, and their
included angle is the same.
3) The three angles are equal.
a) Find the angle JKL.
b) What is the length of GI?
Topic 11 1.5 Trigonometry
Topic/Skill Definition/Tips Example Your turn
1 See 10 1.4 for revision of Pythagoras and Trigonometry.
Find the value of x:
a)
b)
c)
2 Exact Values for
Angles in
Trigonometry
0Β° 30Β° 45Β° 60Β° 90Β°
sin 0
π
π
βπ
π
βπ
π 1
cos 1
βπ
π
βπ
π
π
π 0
tan 0
π
βπ 1 βπ ---
Topic: 11 1.5 Trigonometry
3
H Sine Rule
Use with non right angle triangles.
Use when the question involves 2 sides and 2
angles.
For missing side: π
π¬π’π§ π¨=
π
π¬π’π§ π©
For missing angle: π¬π’π§ π¨
π=
π¬π’π§ π©
π
There is an ambiguous case (where there are two
potential answers).
To find the two angles, use sine to find one, and
then subtract your answer from 180 to find the
other answer.
π₯
sin 85=
5.2
sin 46
π₯ =5.2 Γ sin 85
sin 46= 7.20ππ
sin π
1.9=
sin 85
2.4
sin π =1.9 Γ sin 85
2.4= 0.789
π = π ππβ1(0.789) = 52.1Β°
a) Work out the value of π₯.
Give your answer to 1 decimal place.
b) Work out the size of angle π₯.
Give your answer to 3 significant figures.
4
H Cosine Rule
Use with non right angle triangles.
Use when the question involves 3 sides and 1
angle.
For missing side:
ππ = ππ + ππ β πππππππ¨
For missing angle:
ππ¨π¬ π¨ =ππ + ππ β ππ
πππ
π₯2 = 9.62 + 7.82 β (2 Γ 9.6 Γ 7.8 Γ cos 85) π₯ = 11.8
cos π =7.22 + 8.12 β 6.62
2 Γ 7.2 Γ 8.1
π = 50.7Β°
a) Work out the value of π₯.
Give your answer to 1 decimal place.
b) Work out the value of π₯.
Give your answer to 3 significant figures.
Answers
11 1.1 Polygons and Circles
1) Acute, 65Β° 2) ABD or DBA 3) 125Β° 4) 59Β°
5, 6, 7, 8) a) π₯ = 53Β°, opposite angles are equal π¦ = 53Β° alternate angles are equal.
b) π₯ = 70Β°
9) 84Β° 10) 50Β° 11) 150Β° 16) 540Β°, π₯ = 67Β° 17) 135Β° 18) 60Β° 19) 18Β°
20) π₯ = 130Β°, π¦ = 95Β° 21) 82.5Β° 22) π₯ = 28Β°, π¦ = 60Β°
11 1.2 Statistics 2
1) Mean estimate = 167.9 (1dp)
2) 160 < β β€ 170
4)
5) 35
11 1.3 Algebra 2
1) π‘ =π’+21
4 2) π₯ = 2, π¦ = 6 5) π₯ = β2, π¦ = 2 6) π₯ = 7, π¦ = 3 7) a) π₯ = 3, π¦ = 1 b) π₯ = 0, π¦ = 1 and π₯ = 2.5, π¦ = 1
8) π₯ = 1, π¦ = 4 πππ π₯ = β5, π¦ = β2 9) (π₯ + 4)2 β 15 , Minimum at (β4, β15) 10) 2(π₯ + 2)2 β 6 11) a) π₯ = 4 Β± β13, b) π₯ = 3 Β± β11
2
12) (2, β1) 13) β2 β€ π₯ β€ 5 14) {π₯: β2 β€ π₯ β€ 5} 15) a) 1 b) -7 16) πβ1(π₯) = βπ₯3
β 3
17) a) ππ(π₯) = 2π₯2 + 3, ππ(π₯) = (2π₯ + 3)2 18) (0,0) radius 7, π₯2 + π¦2 = 2
11 1.4 Congruence and Similarity
1) a) Yes b) No 2) Yes, by SAS 5) 45cm 6) a) 65Β° b) 11cm
11 1.5 Trigonometry
1) a) 7cm b) 34.87cm c) 53.7Β° 3) a) 8.13cm b) 35.3Β° 4) a) 17.7 cm b) 80.3Β°
Knowledge Organiser
MATHEMATICS GCSE Mathematics AQA