Rectangle Area Calculator tool is used to calculate area, perimeter and length of the diagonal of a rectangle.

A rectangle is a 2D shape in, having 4 sides and 4 corners. Its two meet at . Thus, a rectangle has 4 , each measuring 90 ĚŠ. The opposite sides of a rectangle have the same lengths and are parallel. Two sides are said to be parallel, when the distance between them remains the same at all points.

Area of rectangle is the product of Length and Width; Area A=L X W or A=a x b.

The perimeter of a rectangle is the sum of its four sides. Since a rectangle has two equal short sides (width, b) and two equal long sides (length, a), perimeter=2a + 2b

A diagonal of a rectangle cuts the rectangle into two right triangles with sides equal to the sides of the rectangle and with a hypotenuse that is the diagonal. By using Pythagorous theorem, we can easily find the length of the rectangle.

Length of the Diagonal=sqrt(Length^{2} + Width^{2})

- Opposite sides are equal and parallel.
- All angles are equal to 90 degrees.
- Opposite sides are equal and parallel.
- All angles are equal to 90 degrees.
- The diagonals are equal and bisect each other.
- The intersection of the diagonals is the circumcentre. That is you can draw a circle with that as centre to pass through the four corners.
- Any two adjacent angles add up to 180 degrees.
- Lines joining the mid points of the sides of a rectangle in an order form a rhombus of half the area of the rectangle.
- The sum of the four exterior angles is 4 right angles.
- The sum of the four interior angles is 4 right angles.
- Join the opposite sides of a rectangle and you get four congruent rectangles of one-fourth the size of the main rectangle.
- Join the midpoints of the sides in order and you get a parallelogram whose sides are parallel to the diagonals.