Given the following diagram, find the required measure.

given: m∠3 = m∠7
m∠2 = 60°
m∠6 = 115°

m∠1 =

a. 110
b. 120
c. 125
d. 130

B. 120°

Step-by-step explanation:

Angles 1 and 2 are supplementary. Therefore  

m∠1 + m∠2 = 180°

m∠1 = 180° - m∠2

m∠1 = 180° - 60°

m∠1 = 120°

The angles with measures m∠1 and m∠2 are supplementary because they lie along a straight line. Since straight angles have measures of 180°, the angles are supplementary.

step-by-step explanation: