10.1 Triangles

Acute TriangleNot Acute Triangles

What is the definition of an acute triangle?

An

swer

An

swer

A triangle with all three angles acute

Right TriangleNot Right Triangles

What is the definition of a right triangle?

An

swer

An

swer

A triangle with one right angle

Obtuse Triangle Not Obtuse Triangles

What is the definition of an obtuse triangle?

An

swer

An

swer

A triangle with one obtuse angle

Triangles can also be classified by the length of their sides

Isosceles Triangle

Equilateral Triangle

Scalene Triangle

A triangle with three congruent sides

A triangle with at least two congruent sides

A triangle with no congruent sides

Draw a line to the correct definition

Interior Angles and Triangles

In any triangle, the sum of the measures of the angles is always 180.

BC

180 °

°

A B A

C

100°

x x°

62

Find the missing angle

1.)

2.)

Write an equation to find the value of x and then find the measurement of each missing angle.

3.)

110o(x + 8)o

(2x + 2)o

5.) The perimeter of a scalene triangle is 65 cm. The length of the first side is twice the length of the second side. The length of the third side is 20 cm. Find the lengths of the missing sides.

Write an equation to find the length of the missing sides.

4.) Perimeter = 64 m

16 m

a.) Draw a pictureb.) Label each sidec.) Write an equationd.) Solve for xe.) Calculate the measure of each side

6.) The ratio of an angle measures of a triangle is 1 : 3 : 5. Find the angle measures. Then classify the triangle by its angle measures. Be sure to write and solve an equation.

7.)

Demonstrate Understanding:

1.)

33o(8y + 3)o

yo

Write an equation to find the missing angles or sides.

2.) The perimeter of an equilateral triangle is 42 in. What is the length of each side?

3.) The ratio of the angle measures of a triangle is 3 : 5 : 12. Find the angle measures. Then classify the triangle by its angle measures.