Question

in figure lines xy bar and mn bar intersect at o.if angle poy=90°and a:b =2:3,find c

Answer 1

Let ∠ a = 2x, then ∠b = 3x

(sum of angle in linear pair always equal to 180° )

∠XOM + ∠MOP + ∠POY = 180°

∠b + ∠a + ∠POY = 180°

given that ∠POY = 90°

plug this value we get  

3x + 2x + 90° = 180°

5x        = 90°

x          = 18°

a          = 2x     = 2 × 18          = 36°

b          = 3x     = 3 ×18           = 54°

MN is a straight line.

sum of angle in linear pair always equal to 180°

so that            ∠b + ∠c         = 180°  

54° + ∠c         = 180°

∠c       = 180° − 54° = 126°

∠ c      = 126°