#### Question

In the below fig, rays AB and CD intersect at O.

Determine y when x = 60°

#### Solution 1

Rays ABand CD intersect at point O.

Therefore, ∠AOCand ∠BOCform a linear pair.

Thus,

∠AOC +∠BOC = 180°

2x +y =180° (1)

On substituting x = 60° :

2x + y = 180°

2(60°) + y = 180°

120° + y= 180°

y = 180°- 120°

y = 60°

#### Solution 2

Given *x *= 60°

*y *= ?

`∠`*AOC*, `∠`*BOC *are linear pair of angles

*`∠`AOC *+ `∠`*BOC *= 180°

⇒ 2*x *+ *y *= 180°

⇒ 2 × 60 + *y *= 180° [ ∵*x *= 60°]

*⇒ y *= 180° -120°

*⇒ y *= 60°

Is there an error in this question or solution?

Solution In the Below Fig, Rays Ab and Cd Intersect at O. Determine Y When X = 60° Concept: Intersecting Lines and Non-intersecting Lines.