Answer:
180
Step-by-step explanation:
A+B+C=180. sum of interior angles of a triangle
The two triangles with the given perimeter is attached .
Perimeter is the sum of all sides.
For the first triangle , sies are 2a,2a and b.
So the perimeter is

For the second triangle, sides are a,a, and 2a+b. Therefore perimeter is

So for both triangles, perimeter is

Answer:
Do not listen to the other answer! Here is how you solve that.
Step-by-step explanation:
For the semicircle, here is the formula for area: 
For the triangle, here is the formula for area:
Then, add.
So,
Triangle:


Semicircle:


Your answer is 