In order to find the value of m, you take into account tha the sum of the known angle and the unknown angle must be equal to 90°. This is becasue these angles are complementary.
Then, you have:
m + 37 = 90
to solve for m you proceed as follow:
m + 37 = 90 subtract 37 both sides
m = 90 - 37
m = 53
Hence, the value of m is 53°
The measure of its supplement angle is calculated by taking into account that two angle are supplementary if they add up 180°. Then, if n is the supplement angle of m, you have:
m + n = 180 subtract both sides m
n = 180 - m replace the value of m
n = 180 - 53
n = 127
Hence, the measure of its supplement angle is 127°
