## Quadrilaterals (Khan Academy)

(1) Quadrilateral proofs & angles Proof: Opposite sides of a parallelogram Proof: Diagonals of a parallelogram Proof: Opposite angles of a parallelogram Quadrilateral angles Proof: Rhombus diagonals are perpendicular bisectors Proof: Rhombus area Area of parallelogram proof Whether a special quadrilateral can exist Rhombus diagonals