Answer: 133.63 square units
Step-by-step explanation:
Pythagoras theorem = a^2+b^2=c^2
10^2 + b^2 = 18^2
b = sqrt (324-100)
b = sqrt 224
Height is to 20 what 10 is to sqrt of 224
h/20 = 10/sqrt 224 (cross multiplication)
h*sqrt 224 = 10*20
h*sqrt 224=200
h = 200/sqrt 224 (200/sqrt 224 = (200*sqrt 224)/200) = 13.36 (height)
Area = (base times height divided by two)
Area = (13.36*20)/2 = 133.63
