Glencoe Math: Course 3, Volume 2
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Glencoe Math: Course 3, Volume 2 View details
6. Changes in Dimensions
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Exercise 12 Page 646

If Solid X is similar to Solid Y by a scale factor, then the volume of X is equal to the volume of Y times the cube of the scale factor.

A

Practice makes perfect

We are given two prisms that are similar. The volume of the first prism is 4 cubic meters and the volume of the second prism is 864 cubic meters. We want to find how many times the second prism is larger than the first prism. To do so, let's start by recalling the relationship between the volumes of similar solids.

Volume of Similar Solids

If Solid X is similar to Solid Y by a scale factor, then the volume of X is equal to the volume of Y times the cube of the scale factor.

In this case, the volume of the second prism is equal to the volume of the first prism times the scale factor raised to the third power. 864 = 4 * x^3 We got an equation that will help us to find the scale factor. Note that the scale factor tells us how many times the second prism is larger than the first prism. Let's solve the equation for x!

864 = 4 * x^3
â–¼
Solve for x
864/4 = 4 * x^3/4
864/4 = 4* x^3/4
864/4 = x^3
216=x^3
sqrt(216)=sqrt(x^3)
6=sqrt(x^3)
6=x
x = 6

Therefore, the scale factor is equal to 6. This means that the second prism is 6 times larger than the first prism and A is the correct option.