Two angles are supplementary. The evaluate of one is 30 more than twice the measure of the other. Determine the measure of the larger angle.

a. 130°

b. 20°

c. 50°

d. 70°

a. If two angles are supplementary, the sum of the measurement of the angles is 180°. ∠1 is shown by x. ∠2 is shown by 2x + 30. Solve the following equation for x; x + 2x + 30 = 180. Simplify; 3x + 30 = 180. Subtract 30 from both sides; 3x = 150. Divide both sides by 3; x = 50. The larger angle is 2x + 30 or 2(50) + 30, which same 130°. If you select b, the equation was set equal to 90 rather than 180 and you solved for the smaller angle. If you select c, x was solved for correctly; thus, this was the smaller of the two angles. If you select d, the original equation was set equal to 90 rather than 180, yet you continued to answer for the larger angle.