If (7,3), (6,1), (8,2) and (p,q) are the vertices of a parallelogram, taken in order, then find the values of p and q.
p = ___ and q = ___
p = 9, q = 4
The point of intersection of the diagonals bisect the diagonals in a parallelogram
First diagonal is formed by the points (7,3) and (8,2)
Point of intersection of the diagonals is the mid point of this diagonal
Hence, the point of intersection is (7+82,3+22) = (152,52)
Now, the other diagonal is formed by the points (6,1) and (p,q)
The mid point of this diagonal is (6+p2,1+q2)
The point of intersection of the two diagonals is the same point
Hence, 6+p2=152
6+p=15⇒p=9
and, 1+q2=52
⇒1+q=5⇒q=4