Question

please question no. 31.

Answer 1

sol.
let AB is the tower and C&D be positions.
then,
AC=a metre and AD=b metres
let,
angle ACB equal to the thetha
then,
triangle DAB,
AB/AD=tan(90°-Thetha)
h/b=cot thetha.......(i)
NOW,
triangle CAB ,we have
AB/AC=tan thetha
h/a=tan thetha
h=a tan thetha.......(ii)
from(i) and (ii),
h square= ab
H=√ab


I hope it's correct answer.
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