the area A(r) (in square meters) of a circular algae colony with radius r meters is given by A(r)=\pi r^2.
The radius M(t) (in meters) after t minutes is given by M(t)=13/3t.
Write a formula for the area Z(t) (in square meters) of the algae colony after t minutes.
It is not necessary to simplify
Z(t)=?

Please help