Answer : The curved surface area of solid cylinder is

Step-by-step explanation :
As we are given that:
Diameter of solid cylinder = 8 cm
Length or Height o solid cylinder = 140 cm
Formula used to calculate the curved surface area of cylinder is:
Curved surface area of cylinder =

where,
r = radius of cylinder
h = height or length of cylinder
Radius of cylinder =

Now putting all the given values in above formula, we get:
Curved surface area of cylinder =

Curved surface area of cylinder =

Therefore, the curved surface area of solid cylinder is
