The elevation of an object on a hill is observed from a certain point in the horizontal plane through its base, to be . After walking towards it on level ground, the elevation is found to be . Then, the height (in metres) of the object is
Step 1: Given data
Angle of elevation=
The angle of elevation after walking =
The distance of walking=
Step 2: Compute the height of the object
Consider the following figure:
Suppose the height of the object is and the distance between the base and the point where observed angle is . So,
Equating equation and ,
Multiply both sides by ,
Substitute value of in equation , as we know that
Thus, the height (in meters) of the object is
Hence, option B is the correct answer.