We can use the Midpoint Formula to find the missing endpoint by splitting the usual formula into two separate equations — one for the x-coordinate and one for the y-coordinate.
M(x,y)=(x_1+x_2/2, y_1+y_2/2)
⇕
x_M=x_1+x_2/2 and y_M=y_1+y_2/2
To find x_2, we can use the x-coordinate of the midpoint, x_M= 5, and the given endpoint, x_1= 9.
The x-coordinate of the endpoint K is 1. Now, we can determine its y-coordinate in a similar process. The y-coordinates of the midpoint and given endpoint are -2 and -5, respectively.
