If the points P(a, -11), Q(5, b), R(2, 15) and S(1, 1) are the vertices of a parallelogram PQRS, find the values of a.

If the points A(a,-11),quad B(5,b),quad C(2,15) and D(1,1) are the vertices of a parallelogram ABCD, find the values of a and b

If P(1, 2), Q(4, 6), R(6, 7) and S(a, b) are the vertices of a parallelogram PQRS, then

Show that points P(1,-2), Q(5, 2), R(3, -1), S(-1, -5) are the vertices of a parallelogram.

If P (1, 2), Q (4, 6), R (5, 7) and S (a, b) are the vertices of a parallelogram PQRS, then

Show that points P(2,-2), Q(7,3), R(11,-1) and S(6,-6) are the vertices of a parallelogram.

If the points A(a ,\ -11),\ \ B(5,\ b),\ \ C(2,\ 15) and D(1,\ 1) are the vertices of a parallelogram A B C D , find the values of a and b .

If P(1,2), Q(4,6), R(5,7) and S(a, b) are the vertices of a parallelogram P Q R S , then