1Explain why the four angles of any quadrilateral add up to 360°.
2Is a square a rectangle? Is a rectangle a square? Explain both answers.
3Where do the properties of a parallelogram come from?
4How can you tell a rhombus from a rectangle just by looking at the diagonals?
5Three angles of a quadrilateral are 90°, 90° and 90°. What is the fourth, and what does that tell you?