Question

Apply the properties of isosceles and equilateral triangles to find the unknown angles in the given figure:

Answer 1

In fig.,

In an equilateral triangle.
each angle = 60°

In an isosceles triangle.,
Let each base angle = a

∴ a + a + 100° = 180°

⇒ 2a + 100° = 180°

⇒ 2a = 180° − 100° = 80°

∴ a = `(80°)/2=40°`

∴ x = 60° + 40° = 100°

and y = 60° + 40° = 100°