Question

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

Answer 1

Let the height of the first pole AB = 6 m. 

Let the height of the second pole CD = 11 m. 

Distance between the poles AC = 12 m. 

From the figure □ ACEB is a rectangle. 

∴ AB = CE = 6 m 

ED = CD – CE = 11 – 6 = 5 m 

Now in △BED; ∠E = 90°; DE = 5 m; BE = 12 m 

BD² = BE² + DE² 

[hypotenuse² = side² + side² – Pythagoras theorem] 

= 12² + 5² 

= 144 + 25

BD² = 169 

BD = √l69 = 13m 

∴ Distance between the tops of the poles = 13 m.