an extension ladder adjusts in length from 10 feet to 16 feet. suppose you've leaned your ladder against your house so that, at its minimum length, it touches the base of your first floor window, 9 feet above the ground. without moving the base, how high will the ladder reach when extended(to one decimal place)?

a^2 + b^2 = c^2

9^2 + b^2 = 10^2
81 + b^2 = 100
b^2 = 19
b = 4.35889

a^2 + 4.3589^2 = 16^2
a^2 + 19 = 256
a^2 = 237
a = 15.4 ft

Check my math.