Question

Please answer question number 10.

Answer 1

m∠A = 180° - 2x

Explanation:

From observation of the given diagram, we can see that angles A, B and C form a straight line.

As angles on a straight line sum to 180°:

`m \angle A + m\angle B + m\angle C = 180^(\circ)`

Given:

`m\angle B = m\angle C =x`

Substitute x into the sum equation in place of m∠B and m∠C:

`m \angle A + x + x = 180^(\circ)`

Simplify:

`m \angle A + 2x = 180^(\circ)`

Subtract 2x from both sides of the equation to create an equation for m∠A:

`m \angle A = 180^(\circ)-2x`