For two adjacent angles with measures x degree and (x+30) degree that makes up a 90 degree angle, what is x?
A. 20
B. 60
C. 15
D. 30
To find the value of x, we can use the fact that the sum of the measures of two adjacent angles that form a straight line (or a 180 degree angle) is equal to 180 degrees.
Since the two angles in question form a right angle (90 degrees), their measures must add up to 90 degrees.
So, we have the equation:
x + (x + 30) = 90
Combining like terms, we get:
2x + 30 = 90
Subtracting 30 from both sides, we have:
2x = 60
Dividing both sides by 2, we get:
x = 30
Therefore, the value of x is 30 degrees.
The correct answer is D. 30.