A Japanese logic puzzle which is perfect for practicing definitions of triangles and quadrilaterals.
Main set of puzzles
More larger puzzles
Finding multiple shapes
Solutions to all puzzles
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+.
Area mazes with solutions
Can be used as Zukei puzzles but also harder questions - calculating the areas of the shapes obtained. Completing Quadrilaterals + Solutions