Question

2. Find the measure of angle A. Make sure to show all work.

Answer:

Answer 1

Angle A measures 80°

Explanation:

Here, the measure of ∠A = (5x + 20)° (given)

From the given picture, the other 2 angles of the triangle measure,

(4x - 3)° and (180 - 125)° = 55° respectively

[Since, opposite angles are equal and sum of two adjacent angles over the same straight-line is 180°]

Now, since the sum of 3 interior angles of any triangle equals 180°, so,

(5x + 20) + (4x - 3) + 55 = 180

⇒ 9x = 108

⇒ x = 12

So, (5x + 20)° =
`(5 * 12 + 20)^(\circ)`

= 80°

So, angle A measures 80°