Three vertices of a rectangle are located on the coordinate plane shown below.

Question

An x y coordinate grid with points A B and C. Point A is at 2 comma 8, point B is at 6 comma 8, and point C is at 6 comma 1.

What are the coordinates of the fourth vertex of the rectangle?

Answer 1

ever think of actually typing the coordinates?
A=(2,8) B=(6,8) C=(6,1)
Clearly, AB is a side of length 4
So, CD must also have length 4, 7 units below AB.
What do you think?

If nothing else, plot the points A,B,C and see where D must be.