Question

The angle of elevation of the top of an incomplete vertical pillar at a horizontal distance of 100 mt. from its base is 45˚. If the angle of elevation of the top of the complete pillar at the same point is to be 60˚, then the height of the incomplete pillar is to be increased by : 

(a) 50√2 mt 

(b) 100 mt 

(c) 100 (√3 − 1) mt 

(d) 100 (√3 + 1) mt

Answer 1

Correct option (c) 100 (√3 − 1) mt

Explanation:

Let BC be the incomplete and BD be the complete pillar. In Δ^s ABC and ABD, we have

∴ The length of the incomplete pillar is to be increased by 100 (√3 − 1) mt.