math
posted by ari .
A circular lake is 30 miles across at its widest point. What is the area of the lake in acres? Round your answer to the nearest tenth of an acre.

A = pi * r^2
A = 3.14 * 15^2
A = 706.5 square miles
1 square mile = 640 acres
706.5 * 640 = ______ acres