Two angles are supplementary and have measures m QRS = (x+40)° and m SRT = x°. What is the measure of QRS?
A. 25°
B. 70°
C. 110°
D. 180°
Since two angles are supplementary, the sum of their measures is 180°. We can write this as an equation:
(x+40)° + x° = 180°
Combining like terms:
2x + 40° = 180°
Subtracting 40° from both sides:
2x = 140°
Dividing both sides by 2:
x = 70°
To find the measure of QRS, we substitute this value back into the expression x+40:
QRS = 70° + 40° = 110°
Therefore, the measure of QRS is 110°, which corresponds to option C.