In quadrilateral ABCD, is angle BCD a right angle?

Each statement is definitely insufficient. The trap lies in the idea that when two right angles opposite to each other is given, there is a general tendency to think that the quadrilateral is either a square or rectangle.

However if you can trace back to childhood, you must have used a typical shaped Kite. This is perfect case of that example. A kite can have two right angles opposite however the other two need not be necessarily right angles. If its difficult to imagine, try to draw a circle first. And then take any point(P) outside the circle(preferably a little far for better visualisation). This is obvious fact that from point P, you can draw two tangents to the circle . And we also know that radius from the centre to that tangent points will be perpendicular at the point of tangency. Now try to join all four sides and make a quadrilateral. You can visualise that angles are not right angles.

Hence the answer is E

So one thing I am starting to pick up on is this ALL shapes on the GMAT can be manipulated, which in turn has huge implications for the answer on DS questions. I suppose this is a bit of a rhetorical question, but are the shapes fixed on the problem solving questions?

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