THE TWO OPP. VERTICES OF A SQUARE ARE (-1,2) AND (3,2). FIND DA CO-ORDINATES OF THE OTHER 2 VERTICES

BD will also have (1, 2) as the mid point. If the vertices of point B is (1,0), then

(x₁+1)/2 = 1

x₁  = 1  

and (y₁+0)/2  =  2   or y₁  =4

or if B has vertices (1, 4), then  y₁ =0.

Thus, either B(1,0) and D(1,4) or B(1,4) and D(1,0).