Hello, TheNcredibleHulk!

Did you make a sketch?

In triangle where and are points on

such that: and , where lies between and

Prove that: .Code:B o * * * * * θ * * * Q * o P * o * * * * * * o * * * * * o C A

Draw line segment .

Let . . . Then

In isosceles

. .

In isosceles

. .

In

Therefore: .