Question

A Vertical stick 10 m long casts a shadow of 20 m on the ground.The length of top of stick and the end of shadow is
a) 100√3 m b) 100√3m c) 25√3 m d) 200√3 m

Answer 1

Answer:

• In ΔABC & ΔADE
• ∠BCA=∠DEA=90
• o
• [Each are at 90
• o
• to the ground]
• ∠BAC=∠DAE [common angle]
• ∠CBA=∠EDA [∵ the sum will cast light a equal angles]
• Hence, by AAA, ΔABC∼ΔADE
• ⇒
• CA
• BC
• =
• EA
• DE
• ⇒
• 10
• 20
• =
• 50
• DE
• ⇒DE=100
• ∴ The height of the tower is 100m.

Answer 2

Answer:

Step-by-step explanation:

In the fig AB is tower and BC =20 m is length of shadow

AC²=10²+20²

=100+400=500

AC=√500=10√5 m