Question

In the below Fig, ∠AOC and ∠BOC form a linear pair. if a − 2b = 30°, find a and b.

Answer 1

Given that,

`∠`AOC and  `∠`BOC form a linear pair

If a - 2b = 30°

`∠`AOC = a°, `∠`BOC = b°

∴a + b = 180°              ..........(i) 

Given a - 2b = 30°                ............(ii)

By subtracting (i) and (ii)

a + b - a + 2b = 180° - 30°

⇒ 3b = 150°

⇒ b = `(150°)/3`

⇒ b = 50°

Hence a - 2b = 30°

a - 2 (50)° = 30°                                    [∴   b = 50°]

a = 30° +100°

a = 130°

∴ a = 130°, b = 50°