Answer:
Angle A measures 80°
Step-by-step 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)° = [tex](5 \times 12 + 20)^{\circ}[/tex]
= 80°
So, angle A measures 80°
