2017 AMC 8 Problems/Problem 22
Problem 22
In the right triangle ,
,
, and angle
is a right angle. A semicircle is inscribed in the triangle as shown. What is the radius of the semicircle?
Solution:
We can reflect triangle on line
This forms the triangle
and a circle out of the semicircle. Let us call the center of the circle
We can see that Circle is the incircle of
We can use the formula for finding the radius of the incircle to solve this problem. The are of
is
The semiperimeter is
Simplifying
Our answer is therefore