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How Do You Find the Surface Area of a Sphere?

Find the surface area of the sphere below:

Summary

  1. 'S' stands for 'surface area'
  2. π is an irrational number which we can approximate to 3.14
  3. 'r' stands for the radius of the sphere
  4. Plug 3.14 in for π and 4 in for 'r'
  5. Since we have an area, our units will be centimeters squared (cm2)

Notes

    1. 'S' stands for 'surface area'
    2. π is an irrational number which we can approximate to 3.14
    3. 'r' stands for the radius of the sphere
    1. π is irrational, which means it is a decimal that goes on forever without repeating
    2. But for this problem, we'll round it to two decimal places so it's easier to work with
    3. The radius of the sphere, 4 cm, is given in our problem
    4. We have everything we need to find S, the surface area!
    1. Now that we know π and 'r', we can plug them into the formula for surface area
    2. Remember, the formula for surface area was S=4πr2
    1. Remember, the formula for surface area was S=4πr2
    2. So when we plug in we get S=4(3.14)(4)2
    1. Use the order of operations to simplify the problem
    1. Since we can multiply these three numbers in any order, we'll multiply the integers first