Question

if the diameter of the Base of right circular cylinder is 14 cm and height is 20 cm, then it's curved surface area is what ?

Answer 1

Diameter = 14 cm, then radius = 7 cm

The surface area of a cylinder can be divided into 2 circles and a rectangle. The curved surface is the rectangle.

Height of rectangle = height of cylinder = 20cm

Width of rectangle = circumference of circle = 2πr = 2π(7cm) = 14π cm²

Curved surface area

Area of rectangle = width * Height = 20 cm * 14π cm = 280π cm² = 879.64594301 cm²

Total surface area

As I said before, 2 circles and a square.

Area of circles = 2πr² = 2π(7 cm)² = 98π cm²

Total = 280π cm² + 98π cm² = 1187.5220231 cm²

Hope this helps you friend
Thanks ✌️ ✌️

Answer 2

r = 7 CM
h =20 CM
curved surface area =2πrh
=2*22/7*7*20
=880 CM^2