Q4 of 45 Page 137

Two poles of heights 18 metre and 7 metre are erected on a ground. The length of the wire fastened at their tops in 22 metre. Find the angle made by the wire with the horizontal.


Let AB and CD be two poles, and AC be the wire joining their top.


and


Angle made by wire with horizontal = ∠CAP = θ [say]


Given,


AB = 7 m [Let AB be smaller pole]


CD = 18 m


AC = 22 m


Clearly, APDB is a rectangle with


AB = PD = 7 m


Also,


CP = CD - PD = 18 - 7 = 11 m


In ∆APC




⇒ θ = 30°


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