I’m bad at math please help me

Answer: x = 48
Step-by-step explanation:
So you have 3 sections there. You have x, 42, and 90 (the square indicates this). Because this is the way it is, a full would be 180. So 42 + 90 = 132
180 - 132 = 48
Answer:
48°
Step-by-step explanation:
Those 3 angles add up to 180 due to the line representing a suplementary angle (180°).
So if we know the measure of two angles, we add them up (42+90) to get 132°,then we subtract this number from 180 to get the angle measure of the 3rd angle which is 48°