Find the total surface area of a cylinder whose height is 4 cm & the radius of whose base is 3 cm.
First you need to make sure you use the correct formula. You have the shape of a cylinder and you are looking for the surface area.
The formula for finding the surface area of a cylinder is 2 times pi times radius squared plus 2 times pi times radius times height.
This may sound complicated but once you know what each part of the formula means you can solve any problem looking for the surface area of a cylinder.
Pi comes from the measurement of the circumference (or perimeter) of a circle divided by the diameter of the circle. It doesn't matter how big or small the circle you still divide the circumference by the diameter. Mathematicians usually use 3.14 as pi because when you use the formula given for finding pi, it comes out to about 3.14 every time.
The radius is one-half of the diameter of the circle. The diameter is the measure from one point one the circle another point and the line segment crosses the center of the circle. The radius is also the measure from a point on a circle to the center of the cirlce.
The first part of the formula: 2 times pi times radius squared comes from finding both the top and bottom of the cylinder. Both are in the shape of a circle so you have to find the area which is pi times radius squared then multiply it twice (for the top and bottom).
The second part of the formula: 2 times pi times radius times height comes from finding the area around the cylinder. The height is the height of the cylinder.
Your question is "Find the total surface area of a cylinder whose height is 4 cm & the radius of the base is 3 cm."
List your variables from the formula: pi, r (radius), h (height)
List your known values for the variables:
pi = 3.14, r = 3, h = 4
Replace the values for the variables:
2 (3.14) (3) (3) + 2 (3.14) (3) (4)
Evaluate using order of operations and you will solve the problem.
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