Question

6. Find the decrease in the length of the shadow of a pole,
when the angle of elevation becomes double. Give that
at this moment, the shadow on the ground of a vertical
pole of 16m high is 64 m.​

Answer 1

The decrease in the length of shadow of the pole is 34 m.

•tan ( angle of elevation ) = (length of pole) / (length of shadow)

tanθ = 16/64

tanθ = ¼

•when angle of elevation becomes doubles, then,

tan2θ = (length of pole) / (length of new shadow)

(2 tanθ)/(1-〖tan〗^2 θ) = 16/ x

8/15 = 16/x

x = 30m

•decrease in the length of shadow of the pole = 34 m