Let $P$ be a point inside rectangle $ABCD$. If $AP = 3$, $BP = 3$, and $CP = 3$, then find $DP$.
British Flag Theorem
AP^2 + CP^2 = BP^2 + DP^2
3^2 + 3^2 = 3^2 + DP^2
9 = DP^2
DP = 3
+297 
