Answer:
m∠A = 78°
Step-by-step explanation:
The question tells us these angles are supplementary meaning they will add up to 180°. We can use the information to make an equation.
m∠A + m∠B = 180
3x + 18 + 5x + 2 = 180
8x + 20 = 180
8x = 160
x = 20
Now we can substitute the solution for x to find the measure of ∠A.
m∠A = 3(20) + 18
m∠A = 60 + 18
m∠A = 78
