Find the unknown complementary or supplementary angle.
-
A)30°
B)50°
C)40°
D)35°

Question

Find the unknown complementary or supplementary angle.
-
A)30° 
B)50° 
C)40° 
D)35°

Quizplus · Accepted Answer

The given angle in the figure is 50°. Since the two lines are parallel, the angle opposite to 50° will also be 50°. Therefore, the sum of the unknown angle and 50° will be 180° (supplementary angles). Solving for the unknown angle, we get: 
Unknown angle + 50° = 180° 
Unknown angle = 180° - 50° 
Unknown angle = 130° 
The complementary angle of 50° is 90° - 50° = 40°, which matches the answer choice C. The unknown angle in the picture is adjacent to a 50º angle, so its complementary angle must be 40º (Option C).

Find the Unknown Complementary or Supplementary Angle