A(3, 3), b(3, 6), and c(7, 6) are three vertices of a rectangle. what are the coordinates of the fourth vertex of the rectangle? .

The vertices of a rectangle are always: (x₁,y₁),(x₁,y₂),(x₂,y₂) and (x₂,y₁)
we have:
(x₁,y₁)=(3,3) ;   x₁=3; y₁=3
(x₁,y₂)=(3,6);    x₁=3; y₂=6
(x₂,y₂)=(7,6);    x₂=7,  y₂=6

The fourth vertex will be (x₂,y₁)=(7,3)

the fourth vertex of this rectanble will be:  (7,3)
        
                 B*(3,6)                    C*(7,6)

                 A*(3,3)                    D*(7,3)