For measurement purposes, a distinction is sometimes made between the base b and the height h of a rectangle :
Either side of a rectangle may be used as a base; the adjacent side will then be the corresponding height.
Based on its properties, a rectangle belongs to the larger category of convex quadrilaterals, which are trapezoids and parallelograms.
- Its two diagonals are congruent.
- Its opposite sides are parallel and congruent.
- A rectangle has two lines of symmetry.
- A rectangle is equiangular.
- The perimeter P of a rectangle with a length of l and a width of w is : P = 2 × (l + w).
- The area A of a rectangle with a length of l and a width of w is : A = l × w.
The opposite sides of this rectangle are congruent.
Its four angles are right angles.