Quadrilateral midpoints

[list][*]Join the midpoints of the sides of the quadrilateral ABCD to form another quadrilateral PQRS.[/*][*]Any observations?[/*][*]Move the vertices of the original quadrilateral ABCD.[/*][*]Any conjectures? [/*][*]Prove your conjectures![/*][*]Can you make a different proof? And another? About the same conjecture? About a different conjecture?[/*][/list]
Conjectures
Proof 1
Proof 2
Proof 3
Additional resources for Proof session
[list][*][url=https://www.geogebra.org/m/sm45zvdq]Harder vector proofs[/url][/*][*][url=https://www.geogebra.org/m/uW9Rcmmj]Pythagorean Theorem Proofs[/url][/*][/list]
– Kathryn Peake

Information: Quadrilateral midpoints