6. A 1.5 m tall boy is standing at some distance from a 30 m tall building. The angle of elevation from his eyes to the top of the building increases from 30° to 60° as he walks towards the building. Find the distance he walked towards the building.
Height of tall boy (DC) is 1.5 m and the height of the building (AB) is 30 m.
According to question,
In right triangle AFD,
So, DF =
In right angle triangle ,
So, distance walked by the boy towards the building = DF - EF =