Problem 920

Find  the surface area and the volume of the cylinder.

cylinder

 

Solution:-

 

For the surface area of the cylinder, remember that it can be unrolled to form a rectangle and two circles.

Find the area of each circle (base).

A = π r2

= 3.14 * 32

= 28.26 cm2

The area of the rectangle can also be determined, since its height is the height of cylinder, and its base length is the circumference of the circle that forms a base.

Find the area of the rectangle.

2πh = 2*3.14*3.7

=131.88 cm2

Find the total surface area.

2*28.26 + 131.88 = 188.4 cm2

Notice that the base of a cylinder is a circle with area π r2.

Thus the volume of the cylinder is π r2h.

Find the volume of the cylinder.

V = π r2h

=3.14*32*7

=197.82 cm3

 

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