Two solved problems to find curved surface area of a frustum of a
cone ,two solved problems to find the total surface area of a frustum
of a cone, two solved problems to find the volume of frustum of a
cone.

Dear Student
The Solution of your first query has been provided below:-

EX-

(1) A cone is cut by a plane horizontally. The radius of circular top and base of frustum are 10m and 3m, respectively. The height of frustum is 24m. If the height of the cone is 28m, then find the lateral surface area of frustum.

Solution: Let, 

Radii are R=r₁ = 10m and r=r₂ = 3m

Height, h = 24m

First we need to find the slant height of frustum, by the formula:

l = √[(r₁ – r₂)² + h²]

= √{(10 – 3)² + 24²}

= √(49 + 576)

= √625 m 

= 25 m

Lateral surface of frustum = π(r₁ + r₂)l

LSA = π(10+3)25

= 325π sq.m.

​​​​​​(​2)Find the curved surface area of a frustum of cone. The slant height is 15 cm, top and bottom diameter is 4 and 10 cm respectively. (Use π = 3)
Solution:-

Curved surface area =lπ×(R+r)

Diameter = radius/2

Radius, R = 20 cm, r = 8 cm

=3×15(20+8)

=3×15(28)

=3×420

=1,260cm2

For remaining query kindly post them in next thread for rapid assistance from our expert.
Regards

 

​​​​​