Rashturi wrote:
Thanks Stuart, I got this question from one of the forums. But how did u know that they are both sufficient, if I were to see a similar question for pentagon hexagon or an optagon, what rule do I apply to find out whether this is sufficient or not.
As a DS question it's definitely inside the scope of the GMAT - it would just be way too time consuming as a PS question.
As long as you were told that the shape were a "regular" pentagon, or hexagon, or whatever, any concrete piece of information would be sufficient to answer almost any question about the shape.
The one thing you have to remember is that if the question asks about a measurement of the shape, you need at least one measurement to even consider sufficiency. Just knowing angles and side proportions is not sufficient (since from angles and proportions we could have a tiny little shape or a huge one).
Here are some examples:
What's the area of the regular hexagon in the diagram below?
(Assume that we have a picture of a hexagon with no information filled in.)
1) Side DE of the hexagon has length 5... sufficient.
2) Angle CDE measures 120 degrees... insufficient.
3) Diagonal AD has length 8... sufficient.
4) The length of side DE plus the length of side EA is twice the length of side BC... insufficient.
It's extremely unlikely that you will see a 5 or greater sided shape on the GMAT that isn't "regular" (except in multiple figure questions, in which case you can divide a weird looking shape into two or more simple shapes).
