Problem Solving (PS) | Re: In square ABCD above, E is the midpoint of side BC. If DE = 8√5, what

We can let DC = n and EC = (1/2)n. Using the Pythagorean theorem, we can determine n:

n^2 + (n/2)^2 = (8√5)^2

n^2 + (n^2/4) = 320

4n^2 + n^2 = 320 x 4

5n^2 = 320 x 4

n^2 = 64 x 4

n = 8 x 2 = 16

Answer: A
...

---