How to Find the Surface Area of Basic 3-D Figures

By eHow Education Editor

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Add some depth to your area of the world.

Instructions

Difficulty: Moderately Easy

Things You’ll Need:

  • Drawing Books
  • Calculators
  • Drafting Compasses
  • Erasers
  • Folders
  • Graph Papers
  • Notebooks
  • Rulers

Cubes, Prisms and Spheres

Step1
Find the surface area of a cube by squaring the length of one side and multiplying the result by 6. Example: The surface area of a cube with side length 3 is 6 x (3 x 3) = 54.
Step2
Calculate the area of each side and find the sum of the areas of all sides to find the surface area of a prism. Example: the surface area of a rectangular prism of height 2, width 3, and length 5 is (2 x 3) + (2 x 3) + (2 x 5) + (2 x 5) + (3 x 5) + (3 x 5) = 62.
Step3
Multiply the square of the radius by pi to find the surface area of a sphere. Then multiply the result by 4. Example: The surface area of a sphere of radius 3 is 4 x pi x 3 x 3 = 113.

Cylinders and Cones

Step1
Find the surface area of a cylinder by first multiplying the radius by 2 times pi.
Step2
Multiply the product by the height of the cylinder.
Step3
Multiply the square of the radius by 2 times pi.
Step4
Find the sum of the results of steps 5 and 6. Example: The surface area of a cylinder of radius 4 and height 5 is (2 x pi x 4 x 5) + (2 x pi x 4 x 4) = 226.
Step5
Determine the surface area of a cone by multiplying the radius of the base by the slant height of the cone.
Step6
Multiply the result by pi.
Step7
Multiply the square of the radius of the base by pi.
Step8
Find the sum of the results of steps 9 and 10. Example: The surface area of a cone with base radius 2 and slant height 4 is (pi x 2 x 4) + (pi x 2 x 2) = 38.

Comments

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Saimon

Saimon said

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sara

sara said

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on 3/28/2007 Thank you so much for your help. It has been a lot of work searching the internet trying to find the right sight for what i needed and then i saw your sight. With hope that this sight was the one i was looking for i clicked on it. I was about to press the back button, but once i saw you had the instructions on how to find the surface area of prisms i was quickly relieved and I knew right away that i wouldn't have to go through any more trouble searching the internet. Again thank you so much for your help and i will always think of you while doing my math homework.

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Anonymous

Anonymous said

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on 1/9/2008 1. Do 2 x pi (3.14) x radius x height. 2. Multiply What ever your radius is by itself. Ex. 3x3, or 12 x 12.
3.Do 2 x pi x radius doubled as shown above.
Radius is 5 and height is 13.
Example: 2 x 3.14 x 5 x 13 = 408.2
2 x 3.14 x 5 x 5 = 157
Then 157 plus 408.2 = 565.2 < Surface Area.

Anonymous

Anonymous said

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on 11/22/2005 Step 1: Find the area of the top and bottom of the cylinder = 2(Pi x r x r).
Step 2: Cut open the cylinder lengthwise, so that the circumference becomes the length of one side = Pi x d = Pi x r x r, multiply this by the length of the cylinder to get the area of that rectangle.
Step 3: Add the answers to steps 1 and 2 together.

Anonymous

Anonymous said

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on 11/22/2005 For cylinders- step 1:You do pie (say3.14)times raidus times 2.
step 2: You do pie (3.14) times the diameter times the height.
step 3: you add the 2 answers you got to get the final answer.

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eHow Article: How to Find the Surface Area of Basic 3-D Figures

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Category: Education

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