GMAT Quantitative Reasoning Practice Test 2

First, draw a rectangular axis system and mark the two points.
The easiest way to find the distance between them is to draw a triangle, where the line CD is the hypotenuse. You can see that the length of one side of the triangle is 5.5 − 2.5 = 3 and the other side is 6.5 − 1 = 5.5. The length of the line CD is
received with the help of the Pythagoras principle.