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📐 Geoboard Area Puzzle

Connect dots to build
a shape with the target area!

Imagine stretching a rubber band across a pegboard (geoboard). Click the dots in order to build a shape, then count grid squares to hit an exact target area. You don't need a formula — just count squares.

A geoboard is a classic teaching tool — nails hammered into a wooden board in a grid, with rubber bands stretched between them to form shapes. Since you can find the area without a formula, it's a great tool for first learning what area even means.

Interestingly, for a shape whose vertices sit on grid points, there's a formula (Pick's theorem) that finds the area just by counting the points inside and on the boundary. On this page, though, we'll build a feel for area first by counting squares directly.

Click the dots in order and a line gets drawn like a rubber band. Click 3 or more dots, then hit "Shape done!" and it automatically connects back to the starting point to close the shape.

When counting area, count a full square as 1 and a triangle cut diagonally in half as half a square (0.5). Made a mistake? Use undo or clear to try again.

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