rektangul

Rektangul is a quadrilateral defined by four interior angles of 90 degrees. It is a type of parallelogram in which adjacent sides are perpendicular, resulting in opposite sides that are parallel and equal in length. If the lengths of the two distinct sides are a and b, the rectangle has opposite sides of lengths a and a, and b and b.

The area of a rektangul is A = a × b, and the perimeter is P = 2(a + b). The diagonals are equal in length and bisect each other, meeting at the rectangle’s center. The length of a diagonal is d = sqrt(a^2 + b^2). Rectangles have two lines of symmetry (the midlines parallel to the sides) and rotational symmetry of order two. A square is a special case of a rektangul where a = b, in which case the shape also has additional symmetry.

Coordinate representations include axis-aligned rectangles with corners at (0,0), (a,0), (a,b), and (0,b). General placements can be described by four vertices in order, and the area can be computed by the shoelace formula. In geometry, rektangul describes the same fundamental shape across various contexts, though terminology may vary by language.

Etymology traces to Latin rectangulus, from rectus (straight, right) and angulus (angle). The concept appears in classical geometry and remains a foundational element in measurements, design, and analysis. Typical applications include architecture, construction, computer graphics, GUI layouts, and map or floor-plan representations.