Respuesta :

Answer:

90

Step-by-step explanation:

A semicircle is 1/2 of a circle

A circle is 360 degrees

1/2 is 180

We have 90 degrees already used on the left

180-90 = 90

b = 90 degrees

Answer:

90

Step-by-step explanation:

The whole thing equals 360

so have equals 180

and half of one 180 is 90 and you're trying to find that half of 180.