Problem $6$: A bird flies overhead from where you stand at an altitude of $310\mathrm{.}0$ m and at a speed horizontal to the ground of $23\mathrm{.}0\frac{m}{s}.$

The bird has a mass of $2\mathrm{.}3$ kg $.$ The radius vector to the bird makes an angle $$ with respect to the ground. The radius vector to the bird and its momentum vector lie in the $xy-$plane. What is the bird's angular momentum about the point where you are standing?