47. A man standing in one corner of a square football field observes that the angle subtend by a pole in the corner just diagonally opposite to this corner is 60°. When he retires 80 m from the corner, along the same straight line, he finds the angle to be 30°. The length of the field is
D. 20√2 m PC = h metreNow, In Δ APC, In Δ PCE, |