Solve the Problem $\sqrt{79} \mathrm{ft} \approx 8.9 \mathrm{ft}$ B) $\sqrt{289} \mathrm{ft} \approx 17.0 \mathrm{ft}$

Solve the problem. Give an exact answer and an approximation to the nearest tenth.
-The diagram below shows the side view of a plan for a slanted roof. Find the unknown length in this roof plan.

A) $\sqrt{79} \mathrm{ft} \approx 8.9 \mathrm{ft}$
B) $\sqrt{289} \mathrm{ft} \approx 17.0 \mathrm{ft}$
C) $\sqrt{289} \mathrm{ft}=144.5 \mathrm{ft}$
D) $\sqrt{23} \mathrm{ft} \approx 4.8 \mathrm{ft}$