How do you know when to use the Triangle Midsegment Theorem in a problem?

Ineed to know the answer to this algebra question.

Write a similarity statement for the similar triangles. afgh ~ a

If you invest 1,500 today in a bank that gives you a 5 percent annual interest rate, which of these items can you buy in two years? a. electronics worth $1,650 b.fitness equipment worth $1,700 c.a holiday package worth $2,000