Consider quadrilateral A B C D. Given that \angle D A C=70, \angle B A C=40, \angle B D C=20, \angle C B D=35. Let P be the intersection of A C and B D. Find \angle B P C.
Consider quadrilateral A B C D. Given that \angle D A C=70, \angle B A C=40, \angle B D C=20, \angle C B D=35. Let P be the intersection of A C and B D. Find \angle B P C.