Two angles are supplementary and have measures m∠QRS=(x+40)° and m∠SRT=x° . What is the measure of ∠QRS ?
Responses:
A. 180°
B. 110°
C. 25°
D. 70°
The sum of the measures of two supplementary angles is 180°.
Given that m∠QRS = (x+40)° and m∠SRT = x°, we can set up the equation:
(x+40)° + x° = 180°
Combining like terms, we have:
2x + 40 = 180
Subtracting 40 from both sides, we get:
2x = 140
Dividing both sides by 2, we get:
x = 70
Therefore, the measure of ∠QRS is x + 40 = 70 + 40 = 110°.
The correct answer is B. 110°.