Question

In the adjoining figure, what is the value of y?
(a) 36
(b) 54
(c) 63
(d) 72

Answer 1

ANSWER:
(b) ${54}^{\circ }$
We have:
$3x+72={180}^{\circ }$ ∵AOB is a straight line⇒3x=108⇒x=36
Also,
$\angle AOC+\angle COD+\angle BOD={180}^{\circ }$

∵AOB is a straight line⇒ ${36}^{\circ }+{90}^{\circ }+y={180}^{\circ }\Rightarrow y={54}^{\circ }$