Answer:AB=15 ,angle A=53.1°,angle B=36.9°
Step-by-step explanation:
AB=√(12^2+9^2)
AB=√(12x12+9x9)
AB=√(144+81)
AB=√(225)
AB=15
TanA=12/9
TanA=4/3
A=Tan(inverse)(4/3)
A=53.1° angle A=53.1°
angle B=180-(90+53.1)
angle B=180-143.1
angle B=36.9°
