There is no formula for a rectangle. There are formula for calculating its area, perimeter or length of diagonals from its sides, or it is possible to calculate the length of one pair of sides given the other sides and the area or perimeter, or the two lots of sides given area and perimeter and so on.
Area of a rectangle: a = l * w
The perimeter of a rectangle is the distance around the rectangle. The area of a rectangle is the space inside the rectangle. To calculate either one you need the length and the width of the rectangle. To calculate the area multiply the length times the width. To calculate the perimeter add the length+width+length+width (that is the distance all the way around)
Calculation of an area depends on what type of area you are trying to measure. The formula for a square (s2) is different for that of a rectangle (lw), which is different from that of parallelogram (bh). See the list of related articles for how to calculate various areas.
2
The area formula for the parallelogram is related to the area formula for a rectangle because you can make the parallelogram into a rectangle to find the area.
The area of a rectangle is calculated by the formula: A = lw (area = length times width). If you know any two of those values, you can insert those values in the formula and calculate the third one.
There is no formula for a rectangle. There are formula for calculating its area, perimeter or length of diagonals from its sides, or it is possible to calculate the length of one pair of sides given the other sides and the area or perimeter, or the two lots of sides given area and perimeter and so on.
The formula for the area of a rectangle is length x breadth. In order to prove this works, work out an area of a rectangle using that formula.
The formula for the area rectangle
You must first calculate the width, using the formula for the area of a rectangle (plug in the numbers you know into the formula, and solve for width). Once you know this, you can plug in the numbers in the formula for a rectangle's perimeter.
Circle = pi x radius squared Rectangle= l x w
If the base is a rectangle, use the formula for the area of a rectangle.
Area of a rectangle: a = l * w
The formula is for a square and rectangle is A=bh or A=lw
A = lw Area of a rectangle = length times width
In the formula for the rectangle, put the width equal to the length.