Rectangle

From Wikipedia, the free encyclopedia

In geometry, a rectangle is defined as a quadrilateral where all four of its angles are right angles.

From this definition, it follows that a rectangle has two pairs of parallel sides; that is, a rectangle is a parallelogram. A square is a special kind of rectangle where all four sides have equal length; that is, a square is both a rectangle and a rhombus. A rectangle that is not a square is colloquially known as an oblong.

Normally, of the two opposite pairs of sides in a rectangle, the length of the longer side is called the length of the rectangle, and the length of the shorter side is called the width.

The area of a rectangle is the product of its length and its width; in symbols, <math>A=lw</math>. For example, the area of a rectangle with a length of 5 and a width of 4 would be 20, because <math>5 \times 4 = 20</math>.

In a rectangle the diagonals cross each other at their respective midpoints, under the same argument as for parallelograms. Unlike general parallelograms the two diagonals of a rectangle have the same length, the length of the diagonal can be found using the Pythagorean theorem.

In calculus, the Riemann integral can be thought of as a limit of sums of the areas of arbitrarily thin rectangles.

[edit] See also

• Cuboid
• Hyperrectangle
• Rectangular function

[edit] External links

• Animated course (Construction, Circumference, Area)
• Eric W. Weisstein, Rectangle at MathWorld.
• Definition and properties of a rectangle With interactive animation
• Area of a rectangle with interactive animationast:Rectángulu

ay:Wiskhalla bn:আয়তক্ষেত্র bs:Pravougaonik bg:Правоъгълник ca:Rectangle cs:Obdélník da:Rektangel de:Rechteck et:Ristkülik el:Ορθογώνιο παραλληλόγραμμο es:Rectángulo eo:Ortangulo eu:Laukizuzen fr:Rectangle ko:직사각형 hi:आयत id:Persegi panjang it:Rettangolo he:מלבן ka:მართკუთხედი sw:Mstatili ht:Rektang lo:ຮູບສີ່ແຈສາກ lv:Taisnstūris lt:Stačiakampis li:Rechhook hu:Téglalap nl:Rechthoek ja:長方形 no:Rektangel nn:Rektangel pl:Prostokąt pt:Rectângulo ro:Dreptunghi qu:Wask'a ru:Прямоугольник simple:Rectangle sk:Obdĺžnik sl:Pravokotnik sr:Правоугаоник fi:Suorakulmio sv:Rektangel ta:செவ்வகம் vi:Hình chữ nhật tr:Dikdörtgen vls:Rechtoek zh:矩形