Question

the length of the shadow of a pole on level ground increases by 90m when the angle of elevation of the sun changes from 58 degree to 36 degree calculate correct to three significant figure the height of the pole

Answer 1

Explanation:

(A) Let a triangle be formed with height of pole h, length of base b and angle of elevation 58°. (Due to lack of a figure).

Tan 58° = h / b = 1.6

(B) Let another triangle be formed with height of pole h, length of base (b + 90) and angle of elevation 36°. (Due to lack of a figure).

Tan 36° = h / (b + 90) = 0.72

(C) Simplifying the two equations :

1.6b = 0.72b + 64.8

b = 64.8 / 0.88 = 73.6 m

h (height of pole) = 1.6 * 73.6 = 117.76 m