Question

prove of lateral surface area of right circular cone

Answer 1

Suppose we have cone shape object like as mentioned in the below diagram

If we cut open it from the slant height the shape of cone will be as follows and the whole area is the curved surface area of cone

This curved surface area is called the lateral surface area of cone or we can also say that

Lateral Surface Area of Cone = Curved Surface Area of Cone

So, formula for lateral surface area of cone is : Π x Radius x Slant Height

or L.S.A. of cone = Π x R x SH

Let's try out some examples to find curved surface area of cone

Example : 1 - Find lateral surface area of cone which has a radius of 3m and slant height of 5m

Solution : Given things are

Radius = 3m

Slant Height = 5m

Value of Π = 3.142

L.S.A. = Π x Radius x Slant Height

L.S.A. = 3.142 X 3 X 5

L.S.A. = 47.13m2

Answer 2

because LSA fomula is 4l2