Question

Find the unknown angles in the given figure:

Answer 1

In the figure,

a = b .........(Angles opposite to equal sides)

But a + b + 80° = 180° .........(Angles of a triangle)

⇒ a + a + 80° = 180°

⇒ 2a + 80° = 180°

⇒ 2a = 180°− 80° = 100°

⇒ a =`(100°)/2=50°`

∴ b = a = 50°

x = a + 80° .......(Exterior angle of a triangle is equal to sum of its opposite interior angles)

= 50° + 80° = 130°

Hence a = 50°, b = 50° and x = 130°