An early counting tool used for basic arithmetic. Inside any quadrilateral a 4-sided flat shape there is a parallelogram opposite sides parallel and equal in length. A to Z index.
Quadrilaterals are a two-dimensional plane figure which has four edges and four vertices.
The polygon has four vertices or corners. Inside any quadrilateral a 4-sided flat shape there is a parallelogram opposite sides parallel and equal in length. A quadrilateral is a closed figure with four straight sides. Quadrilaterals only have one side more than triangles but this opens up an entire new world with a huge variety of quadrilateral types.