Answer:
A. 24
Explanation:
Angles in a triangle add up to equal 180
Thus, 66 + 90 + x = 180
66 + 90 = 156
156 + x = 180
180 - 156 = 24
Hence, x = 24
Note: There is a right angle indicated by the square inside of the triangle. A right angle has a measure of 90 degrees. So Just in case you were wondering that's where the 90 cam from