Question

Consider circle O. If AE = 7, EC = 2, and BE = 4, what is ED?

Answer 1

the answer is D. 3.5

Answer 2

Answer:

D. 3.5

Explanation:

Construct line segment AB and line segment CD. Now look at triangle ABE and triangle DCE. You'll notice that they're similar triangles.

Now, you know that BE corresponds to EC. BE=4 and EC=2. The proportion here is 4:2. That means the lengths of triangle DCE are 1/2 of the lengths of triangle ABE.

You know that AE corresponds to DE. AE is 7 and DE is 1/2 of AE, so DE is 3.5.