Two poles of heights 6 m and 11 m stand on a plane ground. If the distance between the feet of the poles is 12 m, find the distance between their tops.
Given: AD and BE are two poles of height 6 cm and 11 m respectively. D and E are their tops respectively. A and B are their feet respectively such that AB = 12 m.
Required : To find out DE.
Construction: Draw DC ⊥ BE. Join DE.
Determination: ABCD is a rectangle and BC and AD are its opposite sides.
∴ BC = AD
[∵ Opposite sides of a rectangle are equal] = 6 m
Similarly, DC = AB = 12 cm
Now, CE = BE - BC
= 11 m - 6 m = 5 m
Again, in right triangle DCE,
DE
2 = DC
2 + CE
2
[By Pythagoras theorem]= (12)2 + (5)2= 144 + 25 = 169
Hence, the distance between their tops is 13 m.
156 Views
