### Home > MC2 > Chapter 6 > Lesson 6.1.2 > Problem 6-20

6-20.

Similar shapes have sides with equal ratios to each other. To find each unknown side, compare its ratio to a known side.

For example, the ratio of the 15 mm side to the 22 mm side should be equal to the ratio of the *z* side to the 33 mm side.

Now solve for *z*.

*z* = 22.5 mm

You can now use that to find ratios for the other unknown sides.

Write two more ratios to solve for side *x* and side *y*.

15 *y* = (22.5) (54)

*y* = 81 mm

Now what does *x* equal?

Explore the problem with the etool below.

Click the link at right for the full version of the eTool: MC2 6-20 HW eTool