Question

From the top of building AB, a point C is observed on the ground whose angle of depression is 60° and which is at a distance of 40 m from the base of the building. Complete the following activity to find the height of building AB.

From figure, BC = `square`, ∠ACB = `square`

In ΔACB,

tan `square = square/(BC)`

⇒ `square = square/square`

⇒ `square = square`

Hence, the height of the building AB is `square`.

Answer 1

From figure, BC = 40 m, ∠ACB = 60°

In ΔACB,

tan 60° = `bb(AB)/(BC)`

⇒ `bbsqrt(3) = bb(AB)/bb40`

⇒ `bb(AB) = bb(40sqrt(3))`

Hence, the height of the building AB is `bb(40sqrt(3)  m)`.