Answer:
Complementary
x = 55
Explanation:
Complementary angles add up to 90°, while supplementary angles add up to 180°.
In this situation, the two angles add up to 90° (the little box means that an angle is a 90° angle) So, the angles are complementary.
Now, we can write this equation.
x + x - 20 = 90
Simplify.
2x - 20 = 90
2x = 110
x = 55
Just in case, let's check the answer.
Substitute x = 55 into (x + x - 20 = 90)
55 + 55 - 20 = 90
110 - 20 = 90
90 = 90
This is true, so x = 55 is correct.
I hope this helps! Feel free to ask any questions!