A Japanese logic puzzle which is perfect for practicing definitions of triangles and quadrilaterals.
Another Japanese puzzle. Puzzles are pitched at a range of difficulties - the easiest are appropriate for primary (assuming knowledge of area of a rectangle, basic multiplication/division) while the hardest involves some tricky simultaneous equations, maybe yr 11+.
Can be used as Zukei puzzles but also harder questions - calculating the areas of the shapes obtained. Completing Quadrilaterals + Solutions