Find the circumference when the diameter is 12.4cm

Look at attachment. has all info needed. need

Give all possible names for the line shown.calculation tip: lines can be written with either point first.

This is my question~~ ( r ^ 4 - 2r ^ 3 - 23 r ^ 2 - 4r - 32)÷(r+4) ~~ i must use long division to solve it : / i was wondering if anyone world like to solve it. and if so, share step-by-step explanations! you! ❤