When leaned against a vertical structure, a straight ladder can be used safely if its top is no more than 4 above the base of the structure for every foot that the bottom of the ladder is away from the base. How high can a 22-foot ladder safely reach up a vertical structure? Express your answer as a decimal to the nearest tenth.

Question

______feet

Answer 1

h^2 + d^2 = 22^2

h/d = 4 or less

16 d^2 + d^2 = 22^2

17 d^2 = 22^2

d = 5.336
then h is limited to 4 d = 21.3 feet

Answer 2

21.3