Question

The midpoint of AB is M(1,4). If the coordinates of A are (8,7), what are thecoordinates of B?

Answer 1

First you have to draw points A and M and the line between them. Add two lines, one paralel to X and one paralel to Y to form a triangle.

Since M is the midpoint between A and B, this means that the distance between A and M, is equal to the distance between M and B.

Following the same inclination of the line, you have to draw another triangle starting from M with the same heigth and base as the one drawn under segment AM. The hypotenuse of this second triangle will be segment MB.

Now that you know were point B stand in the cartesian system, you can read the coordinates from the graphic.

X-coordinate is -6

Y-coordinate is 1

The coordinates for B are (-6,1)