In geometry, the circumference (from Latin circumferences, meaning "carrying around") of a circle is the (linear) distance around it. That is, the circumference would be the length of the circle The area of a circle is pi (approximately 3.14) times the radius of the circle squared.
(72/80)x90=81
Divide seventy-two by eight and multiply it Ninety.
The circle of radius r centered at (h, k) has equation
.. (x -h)^2 +(y -k)^2 = r^2
Selection A is appropriate.
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It would be helpful if you would use appropriate math symbols. 102 is very different from 10^2. (Copying and pasting does not work--editing is needed.)
If 0, and -8 are the roots of the quadratic equation we can write
(x-0)(x+8)=0
x(x+8)=0
x²-8x=0