Two poles of heights 6m and 11m stand on a plane ground. If the distance between the feet of the poles is 12m, find the distance between their tops.

Let, AE = 11m and BC = 6m are the two poles. E and C are their tops. Construction: Join EC. Since, BC = AD = 6m and AB = DC = 12m ∴ ED = 5m. In △ EDC, By Pythagoras Theorem, EC² = ED² + DC². ∴ EC² = 5² + 12² = 25 + 144 = 169. ∴ EC = 13m. Hence, Distance between their tops = 13m