Question

Apply the property of iscoscles triangle and equilateral triangle to find the unknown Angeles.
If you cannot don't answer​

Answer 1

Solution!!

Mark the ∠a and ∠b, as shown in the attachment.

∠a = ∠b because the sides are equal. If the sides are equal, then the angles are also equal.

The sum of all angles of triangle is 180°. This is the angle sum property of triangle.

∠a + ∠b + 40° = 180° (Angle sum property)

We know that ∠a and ∠b are equal. So, we can write it as 2∠a.

2∠a = 180° - 40°

2∠a = 140°

∠a = 140° ÷ 2

∠a = 70°

∠a = ∠b = 70°

∠a + ∠x = 180° (Linear pair)

70° + ∠x = 180°

∠x = 180° - 70°

∠x = 110°

∠b + ∠y = 180° (Linear pair)

70° + ∠y = 180°

∠y = 180° - 70°

∠y = 110°

The unknown angles x and y are 110° and 110°.