Find two endpoints with Cartesian coordinates. For this example, let the endpoints be (2, 4) and (8, 12).
Subtract the first endpoint's x-coordinate from the second endpoint's x-coordinate, then square the difference. In this example, subtracting 2 from 8 equals 6, and 6 squared is 36.
Subtract the first endpoint's y-coordinate from the second endpoint's y-coordinate, then square the difference. In this example, 12 minus 4 equals 8, and 8 squared is 64.
Add the squared differences together, then calculate the sum's square root to find the distance between the two endpoints. Concluding this example, the square root of 100 (64 plus 36) is 10. The distance between the two endpoints is 10.
Find two endpoints. For this example, let the two endpoints be the same as the previous section.
Add the two points' x-coordinates together, then divide by 2 to find the x-coordinate of the midpoint. In this example, 2 added to 8 equals 10, and half of 10 is 5.
Add the two endpoints' y-coordinates together, then divide by 2 to find the y-coordinate of the midpoint. Concluding this example, 4 added to 12 is 16, and half of 16 is 8. The midpoint is (5, 8).