Hi datonman,

You're referring to this series of posts:

https://www.beatthegmat.com/a-square-wi ... 77233.html

Since I'm the one that you're quoting, I'll be happy to provide some additional info on this math concept. You'll likely find it most helpful to go through the steps, so I'll walk you through them all, but you should physically go through the steps on a piece of paper.

1) Draw a graph.
2) Graph the points (-2, 1) and (-5, -3) and connect these two points with a line segment.
3) Now graph the point (-5, 1). Connect this point to (-2,1) and to (-5, -3). You should now see a right triangle.
4) What are the lengths of the horizontal and vertical lines that you just drew? (3 and 4, respectively).

5) So you have a right triangle with sides of 3 and 4. The third side (the diagonal) has to be 5 (which matches up with what the prompt told us about the square).

GMAT assassins aren't born, they're made,
Rich

Hi datonman,

The deductions here are based on a multi-step process:

1) Since the square has a side length of 5, we can draw a line segment with a length of 5 into the graph as a diagonal line.
2) The two sides of the right triangle that you can draw based on THAT diagonal MUST have side lengths of 3 and 4.
3) "-5" is "3 away" from -2 and "-3" is "4 away" from 1.

It certainly helps having those numbers in the answer choices though.

GMAT assassins aren't born, they're made,
Rich