Question 500755
{{{d = diameter}}}
.
{{{r = radius}}}
.
{{{r = (1/2)d}}}
.
{{{r = (1/2) * 40}}}
.
{{{r = 20 }}}
.
{{{c = circumference}}}
.
{{{c = pi * diameter}}}
.
{{{c = pi * 40}}}
.
{{{c = 40*pi}}}
.
Done.