Question

16. Two lines AB and CD intersect at O. IF AOC °+ COB°+ BOD °= 270º, then AOC
(a) 70°
(b) 80
(c) 90°
(d) 180°
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Answer 1

Answer:

C)90°

Explanation:

Let ∠AOC=x and ∠COB=y. Then, ∠BOD=x and ∠DOA=y.

Now, ∠AOC+∠COB+∠BOD=270 °

⇒x+y+x=270°

⇒2x+y=270°

But, x+y=180°

∴x=y=90°