Polygon: Polygon refers to a closed 2D shape which is made up of a finite number of line segments, but the perimeter is a one-dimensional measurement.

Area of a circle: The area of a circle is the region occupied by the circle in a two-dimensional plane.

Perimeter = Sum of all side lengths

Perimeter of a rectangle = 2 × length + 2 × breadth

P = 2(1 + b) ⇒ (i) l = `P/2` − b, i.e., length = `"Perimeter"/2` − breadth

                         (ii) l = `P/2` − l, i.e., breadth = `"Perimeter"/2` − length

Perimeter of Square = Total boundary of the square

                                   = Side + Side + Side + Side

P = 4 × Side

Or: P = 4s (where 's' represents the side length)

side = ` "perimeter"/"4"`

Always include the correct linear unit (cm, m, mm, km, etc.)

Perimeter of a Triangle = 3 × length of a side.

The perimeter of a regular polygon = (length of one side) × number of sides.

The perimeter of an Irregular polygon = Sum of all sides of Irregular polygons.

Area =  Amount of space inside a flat shape

Area of square = side × side

                          = s × s

                          = s²

Area of square = (side)²

 ⇒ its side = \[\sqrt{Area}\]

Area of a rectangle = length × breadth

Written as: A = l × b

l = `A/b` i.e.,  length = `"Area"/"Breadth"`

and, b = `A/l`  i.e., breadth  = `"Area"/"Length"`

The area of each congruent part = `1/2` (The area of the rectangle)

Area of parallelogram = base x height

Area of triangle = `(1/2) × "base" × "height" = 1/2 × b × h`.

Area of the circle = πr²