Ratios and Proportions

Ratios and ProportionsChapter 7 Section 1ObjectiveStudents will write ratios and solve proportions.RatiosA comparison of two quantities by division

They can be written in three different waysA:BA to BA/B

Turn to Page 432Look at Problem 1

Try the Got It problem for this example.Extended RatioCompares three or more numbers

In the ratio A:B:CThe ratio of the first two is A:BThe ratio of the second two is B:CAnd the ratio to the first and last is A:CTurn to Page 433Look at Problem 3

Try the Got It problem for this example.ProportionAn equation of two (equal) ratios.

Proportions are solve by cross multiplicationExtremesThe first and last numbers in the proportion.MeansThe second and third numbers in a proportionProportionA:B = C:D

A and D are the extremesB and C are the meansCross ProductsFinding the product of the means and the product of the extremes is called cross multiplication or cross products.

It is used to solve a proportion.Turn to Page 434Look at Problem 4

Try the Got It problem for this example.Properties of ProportionsIf A:B = C:D then B:A = D:C

If A:B = C:D then A:C = B:D

If A:B = C:D then A + B = C + D BDTurn to Page 435Look at Problem 5

Try the Got It problem for this example.On page 436.Try problems #1-8 on your ownContinuing on Page 436Complete problems #9-36.Exit Slip/ReflectionCompare/Contrast similar triangles and congruent triangles (at least 6 sentences).

When finished complete #61-65 on page 438.