I need all the help I can get. I don't know how to do any kind of problems like these.

Question

The triangle shown in subdivided into two additional triangles. All three triangles are similar Find the unknown side. Simplify radical answers.

Answer 1

First find the altitude which is the mean proportional between the segments of the base.

Then use the Pythagorean theorem to get your answer.

P.S. You can show that what I said is correct using the similarity of the triangles involved.