Solve for r
r = \frac{40}{\pi} \approx 12.732395447
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1800=\frac{360}{8}\pi r
Multiply both sides of the equation by 2.
1800=45\pi r
Divide 360 by 8 to get 45.
45\pi r=1800
Swap sides so that all variable terms are on the left hand side.
\frac{45\pi r}{45\pi }=\frac{1800}{45\pi }
Divide both sides by 45\pi .
r=\frac{1800}{45\pi }
Dividing by 45\pi undoes the multiplication by 45\pi .
r=\frac{40}{\pi }
Divide 1800 by 45\pi .
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