Question

A school flag pole which is 69m high casts a shadow of 3.2m at about 11am the shadow cast by the school lower at the same time is 18m long. Calculate the height of the tower.

Answer 1

Solution:

Let H be the Height of Flag= 69 meter=AB

Length of Shadow= 3.2 meter=BC

Length of School tower= 18 meter=PQ

Let Length of shadow of tower= t meter=QR

Both the triangles ABC and Δ PQR will be similar.

∠B=∠Q=90°

$\frac{AB}{PQ}=\frac{BC}{QR}$,

because ratio of length of shadow in each case will be same.

$\frac{69}{3.2}=\frac{18}{t}\\\\t=\frac{18\times 3.2}{69}=\frac{19.2}{23}=0.8347$

So, length of shadow of tower= 0.84 meter(approx)