Question

the angle of elevation of the top of a rock from the top and foot of a hundred metre high tower are respectively 30 degree and 45 degree. find the height of The Rock .

Answer 1

Answer:

Step-by-step explanation:

Let the height of the rock is H,

See figure attached below ,

Tan45° = height of the rock/ base length

⇒ 1 = height of try rock/ base length

⇒ height of the rock = base length

⇒ H = L................(1)

Again, tan30° = (H - h)/L

⇒ 1/√3 = (H - 100)/H

⇒ H = √3(H - 100)

⇒ 100√3 = √3H - H

⇒ H = 100√3/(√3 - 1) = 100√3(√3 + 1)/(√3² - 1²)

H = 50√3(√3 + 1) = 50(3 + 1.732) = 50 × 4.732

H = 236.6 m

Answer 2

here is your answer