## Intermediate Algebra (12th Edition)

$(a)~d=5$ in $(b)~C=5\pi$ in
(a) We know that the diameter relates to the radius by the formula: $diameter=2*radius$ $d=2r$ We plug in $r=2.5$ in: $d=2*2.5=5$ in (b) We know that the circumference of a circle is given by the formula: $Circumference=2\pi~radius$ $C=2\pi r$ We plug in $r=2.5$ in: $C=2\pi~2.5$ $C=5\pi$ in