You have a circular pool that has a circumference of 100ft. You need to buy a cover for the pool. How many square feet of material for the cover is needed?

Question

More geometry..... I so can't wait to finish this class! 

 

 

~Hope

Answer 1

You have a circular pool that has a circumference of 100ft. You need to buy a cover for the pool. How many square feet of material for the cover is needed?

 

For a circle:

      C = Πd = 2Πr                             [C=circumference; d=diameter; r=radius; Π = pi]

      A = Πr²

 

Now, since the problem give C, can we put the formula for area in terms of C ??

      A = Π((C/(2Π))² = C²/(4Π)

 

When C=100,

      A = (100*100)/(4*3.14159) = 2500/3.14159 = 795.78 sq. ft. 

 

(Sometimes, it helps to do the calculations after simplifying the formula with constants/variables)

Answer 2

Well, Hope, I'm sure you'll never have to deal with geometry again, like buying the right sized cover for your pool.

 

Circumfrence = pi x the diameter

100/pi = diameter

diameter = 31.84

 

Area = pi x radius²

Area = pi x 15.92²

Area = 795.82