Question 10
Rectangle $ABCD$ has side lengths $AB = 84$ and $AD = 42.$ Point $M$ is the midpoint of $\overline{AD},$ point $N$ is the trisection point of $\overline{AB}$ closer to $A,$ and point $O$ is the intersection of $\overline{CM}$ and $\overline{DN}.$ Point $P$ lies on the quadrilateral $BCON,$ and $\overline{BP}$ bisects the area of $BCON.$ Find the area of $\triangle CDP.$