# Review 2.2,2.5,3.5,4.1,5.7 #21

### A. Wachowicz in Mr.Kirkland's Math II honors class

A surveyor needs to measure the distance, AB, across the lake. Beginning at E, he locates the midpoint, C, of AE and the midpoint, D, of BE. He then measures CD. What is AB?

To help solve this problem you can use a brace map to help you organize the steps.

Where the problem gives you the midpoint multiply the midpoint by 2 to get the measure of the third side.