Thread: Need help for geometry proof

I need to write a proof and prove that: any triangle inscribed in a semicircle is a right triangle.

I realize that it is right, but I am unsure how to prove that it is true.

Can anyone help me with an idea of where to start?

Thanks.

Realize that the diameter of the circle is the hypotenuse of the triangle.
Any inscribed angle in a circle measures one-half the intercepted arc.
But that is the “other” semicircle which measures .

I'm confused with what the intercepted arc is and therefore both the second and third lines confuse me.