Question 795212
{{{ 66*400 }}} = the circumference
of the pond in cm
Use formula {{{ C = 2*pi*r }}}
where {{{ r }}} = radius
{{{ 66*400 = 2*pi*r }}}
{{{ r = ( 66*400 ) / ( 2*pi ) }}}
The diameter is twice the radius, so
{{{ d = ( 66*400 ) / 3.141 }}} cm
You can finish calculation