In the figure, OC ⟂ OA (dashed) and D, O, A lie on a straight line. For the orange angle x = ∠AOB, c is its complement and s is its supplement. If s=4c, find x.
Class 7Complementary and Supplementary AnglesLines and Angles
A30°
B45°
C120°
D60°
Step-by-Step Solution
s=180∘−x and c=90∘−x. So 180−x=4(90−x)⇒180−x=360−4x⇒3x=180⇒x=60∘.
Answer: D) 60°
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