Question

three vertices of a kite are (0,0) -6,8) and (10,0) what are the coordinates of the fourth vortex?

Answer 1

Notice the distance from vertix to either point is 10. So the fourth point must lie along the line from vertix to some pont equidistance from the two other points.

Now looking at the points plotted, the line equidistant from both points is at 45 degrees from the x axis. The other two sides of the kite just have to be longer than 10, so pick a point on that line.