Hi Newaz111,
You might find it beneficial to draw a couple of quick sketches - they'll likely help you to answer the question faster.
We're told that a rectangle is drawn into the xy-plane and the the sides of the rectangle are PARALLEL to the axes. We're also told that one of the 4 vertices is located at (-1,-2). We're asked for the PERIMETER of the rectangle. To answer this question, we need to know the other 3 vertices...
Fact 1: One of the vertices is (2, -2).
If you draw the original point (-1,-2) and this point (2,-2), you'll end up with a STRAIGHT LINE. This gives us the length of 2 of the sides, but NOT the other two.
Fact 1 is INSUFFICIENT
Fact 2: One of the vertices is (2,3).
If you draw the original point (-1,-2) and this point (2,3), you'll end up with a DIAGONAL LINE. You can use this diagonal line to figure out the other 2 vertices (remember, the sides of the rectangle are PARALLEL to the axes).
The vertices would be (-1,-2), (2,3), (2,-3) and (-2,3) so we could calculate the perimeter (it would be 4+4+6+6 = 20, but that math is unneccesary).
Fact 2 is SUFFICIENT
Final Answer: B
GMAT assassins aren't born, they're made,
Rich
