Answer:
4pi in^2
Step-by-step explanation:
Lateral surface area of a cylinder = 2πrh
π = pi
r = radius
h = height
Let me illustrate with an example
A cylinder has the following dimensions
r = radius = 20
h = height = 10
lateral area = 2 x π x 20 x 10 = 400π
If dimensions are reduced to one-fifth their original length, new dimensions are
r = radius = 20 x 1/5 = 4
h = height = 10 x 1/5 = 2
New lateral area = 2 x 4 x 2 x π = 16π
change in lateral area = 400π / 16π = 25
If dimensions are reduced by 1/5, lateral area would reduce by 25
100 pi / 25 = 4
