Fantasia decided to paint her circular room which had a diameter of 25 feet. She started painting in

Discussion in 'Calculator Requests' started by math_celebrity, Dec 2, 2022.

  1. math_celebrity

    math_celebrity Administrator Staff Member

    Fantasia decided to paint her circular room which had a diameter of 25 feet. She started painting in the center and when she had painted a circle with a 5-foot diameter, she used one quart of paint. How many more quarts of paint must Fantasia buy to finish her room?

    The area formula for a circle is:
    Area = pir^2

    Area of full room
    Radius = D/2
    Radius = 25/2
    Radius = 12.5
    Area = 3.1415 * 12.5 * 12.5
    Area = 490.625

    Area of 5-foot diameter circle
    Radius = D/2
    Radius = 5/2
    Radius = 2.5
    Area = 3.1415 * 2.5 * 2.5
    Area = 19.625

    So 1 quart of paint covers 19.625 square feet

    Area of unpainted room = Area of Room - Area of 5-foot diameter circle
    Area of unpainted room = 490.625 - 19.625
    Area of unpainted room = 471

    Calculate quarts of paint needed:
    Quarts of paint needed = Area of unpainted Room / square feet per quart of paint
    Quarts of paint needed = 471/19.625
    Quarts of paint needed = 24 quarts
     

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