∠A = 24°
∠B = 87°
∠A = 24°
Step-by-step explanation:
The sum of angles in a triangle is 180 degrees
let measure of angle A = ∠A
∠B = 15 more than three times the measure of angle A
∠B = 15 + 3∠A
∠C = 45° more than the measure of angle A
∠C = 45° + ∠A
∠A + ∠B + ∠C = 180° (sum of angles in a triangle)
∠A + 15 + 3∠A + 45° + ∠A = 180
collect like terms:
∠A + 3∠A + ∠A + 15 + 45 = 180
5∠A + 60 = 180
5∠A = 180 -60
5∠A = 120
∠A = 120/5
∠A = 24°
∠B = 15 + 3∠A = 15 + 3(24)
∠B = 87°
∠C = 45° + ∠A = 45° + 24°
∠C = 69°