Try this Drag the orange dots on each vertex
to reshape the square.
The square is probably the best known of the quadrilaterals.
It is defined as having all sides equal, and its interior angles all right angles (90°).
From this it follows that the opposite sides are also parallel.
A square is simply a specific case of a regular polygon, in this case with 4 sides.
All the facts and properties described for regular polygons apply to a square.
See Regular Polygons
The vertex (plural: vertices)
is a corner of the square. Every square has four vertices.
The distance around the square. All four sides are by definition the same length, so the perimeter is four times the
length of one side, or: