Question 1098422
Tracing out 1 complete revolution on the ground
is the circumference, {{{ C = 2*pi*r }}} of the wheel.
You are given:
{{{ 12 = 2*pi*r }}}
{{{ r = 12 / ( 2*pi ) }}}
{{{ r = 6 / 3.141 }}}
{{{ r = 1.9099 }}} 
The radius of the wheel is 1.91 ft