Question

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

Answer 1

AC are the opposite vertices and BD are the opp vertices so use midpoint formula

a+2/2,-11+15/2.This is for AC

5+1/2,B+1/2.This is for BD.

now u can find d answer

Hope it helps u...