From a point Y on a level ground, the angle of elevation of the top of a lamp post is 45°. If the distance of point Y from the foot of the lamp post is 80 m, the height of the lamp post will be :

Correct option is B

Given:
Angle of elevation = 45°
Distance from point Y to the base of the lamp post = 80 m
Concept Used:
In a right-angled triangle, if the angle of elevation from the point on the ground to the top of an object is known, and the distance from the point to the base is given, then the height can be found using trigonometric ratios.
Formula Used:
​$$\tan(\theta) = \frac{\text{Height of the object}}{\text{Distance from the point}}$$​​
Solution:

​$$\tan(45^\circ) = \frac{h}{80} \\1 = \frac{h}{80} \\h = 80\, \text{m}$$​​