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Topic: Ratios and ProportionsEssential Question: How are ratios and proportions relevant in the real world.

Get a new assignment sheet from the back table and fill it out.Get out your HSAP reviewGet a calculatorTake out a sheet of paper for notes

Geometry Table

of ContentsUnit: Similarity

Assignment/Page

#Date Topic/Section title Activity

1 3/14-3/19Notes - Ratios and

proportionsNotes

2 3/14-3/19 One Foot Tall Activity

3 3/14-3/19

w.s. ratios and

proportions #

1-3, 17-26,

29-30, 39-42 all

Homework

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Answers to HSAP reviews - Probability and Statistics

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In the fraction a b

a is called the ____________b is called the ____________

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a to b a:b

Ratios should be reduced but not converted toa whole number. For example, the ratio 4/2 shouldbe written as 2/1, not 2. Without two numbers, youdon't see the comparison any more.

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General form ofa proportion.

The product of the means is equal to the productof the extremes.

When you are multiplying the means and extremes together you are cross-multiplying.

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What does it mean to be proportional?

Answer: For two ratios to be equal.

How do you determine whether two ratios form aproportion?

Answer:1) Convert the ratios to decimals to see if the ratioshave the same value

2) See if you get the same product when you crossmultiply.

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Determine whether the following ratios forma proportion.

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If a does

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Equivalent proportionsIf the product of the means is equal to theproduct of the extremes (if you get the same valuesfor two proportions when you cross multiply) for twoproportions, the proportions are said to be equivalent.

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Ways to get equivalent proportions1) Reverse the left and right sideof a proportion.2) Reverse the numerators and denominators of eachratio in the proportion3) Reverse the extreme values4) Reverse the mean values5) Add or subtract the numerator from the denominator for both denominators of the proportion.6) Add or subtract the denominator from the numerator for both numerators of the proportion.

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Examples: If a/b = c/d, then these proportions are equivalent to them.

1)

2)

3)

4)

5)

6)

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Solving Ratio word problems

1) Make monomials out of the numbers in the ratios by putting x behind then.

2) Set the monomials to add to be the totals.

3) Solve for x.

4) Plug x back into the monomials to find the lengths, or values.

Why does making moniomials with x allow us to solve theproblem?

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The angle measures of a triangle are in the ratio of 3:4:5. Find the measure of each angle of the triangle.

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Proportions with three ratios

Suppose you are given the following proportion with three ratios.

4 = x = 14 3 10 y

1) Make a proportion to solve for x using the ratio with no variables.

2) Make a proportion to solve for y using the ratio with no variables.

Example:

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Activity: One Foot tall

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Homework: Finish your "One Foot Tall" worksheet

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