Question

A flag pole 18 m high casts a shadow 9.6 m long. Find the distance of the top of the pole from the far end of the shadow.

Answer 1

Let MN = 18 m be the flag pole and its shadow be LM = 9.6 m.

The distance of the top of the pole, N from the far end, L of the shadow is LN.

In right-angled ∆LMN,

LN² = LM² + MN²  ......[By Pythagoras theorem]

⇒ LN² = (9.6)² + (18)²

⇒ LN² = 9.216 + 324

⇒ LN² = 416.16

∴ LN = `sqrt(416.16)` = 20.4 m

Hence, the required distance is 20.4 m