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Maths Exercices

Surface Area

What is the surface area of this cylinder? Use π ≈ 3.14.

Remember that

Surface area of a cylinder:

Surface area = Atop + Abottom + Aside

Find the radius and height of the cylinder.

radius = 5
height = 4

Find the area of the circle on the top of the cylinder. Use 3.14 for π.

Atop = πr2

3.14 ×
5 × 5

78.5

The circle on the bottom of the cylinder is the same, so:

Abottom =
Atop 78.5

Find the circumference of the top circle.

C = r

2 ×
3.14 × 5

31.4

Now find the area of the curved surface. The curved surface is a rectangle. One side length is the height, and the other side length is the circumference of the circle.

Aside =
C × h

31.4 × 4

125.6

Now add the areas to find the surface area of the cylinder.

Surface area = Atop + Abottom + Aside

78.5 +
78.5 + 125.6

282.6

The surface area of the cylinder is about 282.6 square millimeters.



What is the surface area?

20 in

26 in

4 in




Surface Area = in2