This week in math, we finished our 7th unit in relations and started the 8th unit going into further detail about it, and learned about distances between our graphing points.
To aid us in this, we were given a new website to use called DESMOS, here is the provided link:
https://www.desmos.com/calculator
This is simply a freeplay cartesian plane grid to map your points out and see how they stack up to one another on the x and y axis, and as we learned, in distance.
To find distance between points, we need to see the x and y values, a great part of DESMOS is that they label these, making it very easy, you want to look for matching x or y values in the 2 points you are looking for distance between, because that makes it easier since it will be a straight line,
(Ex. – trying to find distance between points G and H. G(3,7) H(7,7) because the y values are the same (7), we only need to look at the x values, we subtract the smaller one from the bigger one (7-3=4) (we do this for 7 too but it wont matter because it will be 0) and square the results from that 
If neither the x values or the y values are the same, we have to do a bit more work. Since the x and y values are different, we know its a diagonal line, and seeing as we know the height and length of each point, we can create horizontal and vertical lines to make it look like a right triangle.
lets say you were finding the distance between A and B and you had two different x and y values so you are finding the length of side c, and you can draw these 2 lines to make it a right triangle, and because its diagonal you will always be finding the hypotenuse. So since we know the horizontal and vertical distances by subtracting them, we can fill out the sides a and b, and use Pythagoras to find side c since its a right triangle.
(Ex. point A(2,4) point B(5,8) So we use Pythagorus – 
I hope this post helps you in finding distances on cartesian planes more easily, thank you for reading.