Main content
Intro to quadrilateralRight angles in shapes (informal definition)Identifying quadrilateralsQuadrilateral propertiesQuadrilateral typesClassifying quadrilateralsKites as a geometric shapeQuadrilaterals review
Proof: Opposite sides of a parallelogramProof: Diagonals of a parallelogramProof: Opposite angles of a parallelogramProof: Rhombus diagonals are perpendicular bisectorsWhether a special quadrilateral can existRhombus diagonals
Test your understanding of Quadrilaterals with these 9 questions.

About this unit

Quadrilaterals only have one side more than triangles, but this opens up an entire new world with a huge variety of quadrilateral types. Learn about it here.