Is quadrilateral ABCD a rectangle?

[Brent@GMATPrepNow]

Here's a question I made up. See how you do.

Is quadrilateral ABCD a rectangle?

(1) The diagonals (AC and BD) are perpendicular to each other
(2) The sum of any 3 angles in the quadrilateral is 270 degrees

Answer: B

[melguy]

Statement 1

Square and Rhombus both share this property. Insufficient

Statement 2

In rhombus opposite angles are equal so we can rule it out. Rectangle and square share this property but I believe GMAT considers Square as a special rectangle so it should be sufficient.

[Brent@GMATPrepNow]

That's correct; a square is a type of rectangle. So, if the quadrilateral is a square, then we can also conclude that the quadrilateral is a rectangle.

From the Official Guide:
A parallelogram with right angles is a rectangle, and a rectangle with all sides of equal length is a square.

For more on this topic, here's a video:
- Quadrilaterals: https://www.gmatprepnow.com/module/gmat ... /video/874

Cheers,
Brent