A 5 by 4 rectangle

In geometry, a rectangle is defined as a quadrilateral where all four of its angles are right angles. Image File history File links Rectangle4x5. ... Image File history File links Rectangle4x5. ... For other uses, see Geometry (disambiguation). ... This article is about the geometric shape. ... This article is about angles in geometry. ...

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. A parallelogram. ... For other uses, see Square. ... Two rhombi. ... In geometry, a rectangle is a defined as a quadrilateral polygon in which all four angles are right angles. ...

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, A = lw. For example, the area of a rectangle with a length of 5 and a width of 4 would be 20, because . This article is about the physical quantity. ...

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. A parallelogram is a four-sided plane figure that has two sets of opposite parallel sides. ... In mathematics, the Pythagorean theorem (AmE) or Pythagoras theorem (BrE) is a relation in Euclidean geometry among the three sides of a right triangle. ...

In calculus, the Riemann integral can be thought of as a limit of sums of the areas of arbitrarily thin rectangles. For other uses, see Calculus (disambiguation). ... In the branch of mathematics known as real analysis, the Riemann integral â„›, created by Bernhard Riemann, was the first rigorous definition of the integral of a function on an interval. ... Wikibooks Calculus has a page on the topic of Limits In mathematics, the concept of a limit is used to describe the behavior of a function as its argument either gets close to some point, or as it becomes arbitrarily large; or the behavior of a sequences elements as... 3 + 2 = 5 with apples, a popular choice in textbooks[1] This article is about addition in mathematics. ...

See also

• Rectorsal
• Cuboid
• Hyperrectangle
• Rectangular function
• Square (geometry)

In anatomy, the cuboid bone is a bone in the foot. ... This article does not cite any references or sources. ... The rectangular function (also known as the rectangle function or the normalized boxcar function) is defined as or in terms of the Heaviside step function The rectangular function is normalized: The Fourier transform of the rectangular function is where sinc is the sinc function. ... For other uses, see Square. ...

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 animation