What makes a shape a triangle, a square, or a circle?
Shape Club Rules
What makes a shape a triangle, a square, or a circle?
Look around any room and you'll find them everywhere: triangles, squares, circles. We name them instantly, without thinking. But what actually makes a triangle a triangle? It turns out shapes have rules — secret club memberships, really — and once you know the rules, you can spot exactly why each one belongs.
Let's start with the simplest idea: a straight line, a fence post laid down flat. One line alone is lonely. It doesn't close anything in. To make a shape, you need lines that join up and box in some space — like a fence that comes all the way back to where it started.
