To find the distance across a river, a surveyor chooses points A and B, which are x = 400 ft apart on one side of the river (see the figure). She then chooses a reference point C on the opposite side of the river and finds that ∠BAC ≈ 82° and ∠ABC ≈ 52°. Approximate the distance from A to C. (Round your answer to the nearest foot.)