Half Area Quadrilateral

Half Area Quadrilateral

Make three equally spaced notches along the four sides of a square. Choose one of these three notches on each side. Connect them up to form a simple quadrilateral. For example, here we have chosen the middle notch on each side. What is the area of this...
Arrows

Arrows

Arrows (Eggleton & Fraenkel, 1975) Categorize 9 games based on the answer to two questions: 1) Will Emperor Jiaqing win / tie / lose if he goes the first. 2) Will the Pirate, Ching Shih, win / tie / lose if she goes the first. The games are all variants of the...
Venn Diagram Puzzles

Venn Diagram Puzzles

Venn diagrams are not taught well anywhere. With little effort, these diagrams can be brought to life with beauty and by going beyond that little 3 circle Venn diagram. At the very least a teacher should end a lesson on the three circle Venn diagram with a question:...