Answer:
x = 21
Upper angle has a measure of 69°
Lower angle has a measure of 21°
Explanation:
The two angles form a right angle ( indicated by the little square )
A right angle has a measure of 90 degrees.
This means that (x + 48) + x must equal 90
Note that we've just created an equation that we can use to solve for x
We now solve for x using that equation
x + 48 + x = 90
combine like terms
2x + 48 = 90
subtract 48 from both sides
2x = 42
divide both sides by 2
x = 21
We then plug in x to find the measures of the angles
x + 48
x = 21
21 + 48
= 69
The other angle simply equals 21°