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The larger circle has a radius that is 18 inches longer than the smaller circle. The larger circle has a circumference that is A pi feet larger then the smaller circle. find the value of a.

  • math -

    Radius of smaller circle: a-18 (inchs)

    Radius of larger circle: a (inchs)

    Circumference of smaller circle:
    2*pi*(a-18)=2*pi*a-2*pi*18=2*pi*a-36*pi (inchs)

    Circumference of larger circle:
    2*pi*a (inchs)

    Difference betwen ircumference of smaller and large circle:

    D=2*pi*a-(2*pi*a-36pi)=
    2*pi*a-2*pi*a+36pi=
    36*pi (inchs)

    D=36*pi (inchs)

    1feet=12 inchs

    D=(36*pi)=(3*pi)ft

    D=(A*pi)

    A*pi=3*pi Divide with pi

    A=3

  • math -

    D=(36*pi)in=(3*pi)ft

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