Answer:
m∠A+m∠B = m∠ACD.
m∠A = 56°
m∠B = 97°
Explanation:
In this problem, we are given that m∠B is fifteen less than twice the m∠A.
Let m∠A = x°
This means that m∠B = 2x°-15°
Due the exterior angles theorem,
m∠A+m∠B = m∠ACD.
Since we are given that m∠ACD is 153°,
m∠A+m∠B=153°.
x+2x-15=153
x=56°
That means
m∠A = 56°
m∠B = 2(56) -15
m∠B = 97°