# Calculate area of hollow cylinder

## ( Equivalent to: surface area of hollow cylinder )

In next fields, kindly type the dimensions of your shape in the text box under title [ Unknowns: ]. After you type your value, click "CALCULATE" button; the answer will be automatically calculated and displayed in the text box under title [ Answer: ]. Also, you will be able to animate your shape through buttons under the below figure.

## How to Calculate Area Of Hollow Cylinder

*Example: What is the area of hollow cylinder with outer-radius = 25 units, inner-radius = 24 units and altitude = 31 units?*

As;

area of hollow cylinder = 2*π*((outer-radius)^{2}-(inner-radius)^{2})+2*π*(outer-radius+inner-radius)*altitude

By substituting the above given data in the previous function;

(i.e.) = 2*π*((25)^{2}-(24)^{2})+2*π*(25+24)*31

Answer is: units^{2}.

*Practice Question: Calculate area of hollow cylinder for the following problems:*

N.B.: After working out the answer of each of the next questions, click adjacent button of see the correct answer.

( i ) outer-radius = 25 units, inner-radius = 24 units and altitude = 32 units

( ii ) outer-radius = 25 units, inner-radius = 22 units and altitude = 33 units

( iii ) outer-radius = 25 units, inner-radius = 22 units and altitude = 33 units