DS

[ricaototti]

OA E
Is quadrilateral ABCDa square?
(1) All four sides of ABCD are the same length.
(2) Two of the adjacent angles of ABCD add up to 180 degrees.

[pepeprepa]

In 1), in 2) and in 1)&2) take the example of a lozenge.

[loki.gmat]

"every square is a rhombus but not every rhombus is a square".

statement1 alone - ABCD can be a rhombus or a square.

statement2 alone - ABCD can be a rhombus or a square or a rectangle.

stat1 & 2 - ABCD can be a rhombus or a square.


hence IMO E.



Thanks!

[ricaototti]

can u tell me the properties of a rhombus please

[mals24]

Properties of Rhombus

All sides are equal - this is the basic property of a rhombus.

Area of a rhombus = base * altitude.

The diagonals of a rhombus always bisect at 90 degrees.

All squares are rhombuses but all rhombuses are not squares


A square is a rhombus whose: 1) all sides are equal
2) all angles are right angles.

Hence to find out if a figure is a rhombus we just need information about the sides.

And to find out if a figure is a square we need information about both the sides and the degree measure of all angles.

This question gives us information regarding sides only whereas nothing about the degree measure of the angles is mentioned hence the answer is E

Hope that helps