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A Guide to the GRE/Quadrilaterals
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Quadrilaterals
The angles of a quadrilateral add up to 360º. There are 6 key types:
Square Rectangle Four equal, 90º angles ✓ ✓ Four equal sides ✓ ✗
Rhombus Parallelogram Opposing sides are parallel ✓ ✓ Diagonal angles are equal ✓ ✓ Adjacent angles add up to 180º ✓ ✓ All four sides are equal ✓ ✗
Trapezoid
One set of parallel sides
Kite
Two sets of adjacent equal sides