# Circumference Calculator

Circle

Triangle

Square

Rectangle

Rhombus

Parallelogram

Ellipse

## How To Use Circumference Calculator

Lets first understand, what is circumference and how we can calculate circumference of various 2-D shapes?

Circumference

The circumference is the perimeter of a circle or ellipse, that means, the circumference would be the arc length of the circle, as if it were opened up and straightened out to a line segment. Generally, the perimeter is the curve length around any closed figure.

Circle

A circle is a shape consisting of all points in a plane that are at a given distance from a given point, called the center of the circle.

The circumference of a circle is the distance around it.

The ratio of a circle's circumference to its diameter is $$\pi$$, a constant approximately equal to 3.14159.

Let the Radius be $$R$$ units.

Circumference will be $$2\pi R$$ units.

Triangle

A triangle is a polygon with three edges and three vertices.

Any three points, when non-collinear, determine a unique triangle and simultaneously, a unique plane.

Let the three sides be $$A$$, $$B$$ and $$C$$ units.

Perimeter (circumference) will be $$(A+B+C)$$ units.

Square

A square is a regular quadrilateral, means that it has four equal sides and four equal angles.

Let the Side Length be $$L$$ units.

Perimeter (circumference) will be $$4L$$ units.

Rectangle

A rectangle is a quadrilateral with four right angles and with equal opposite sides.

Let the Length and Width be $$L$$ and $$W$$ units respectively.

Perimeter (circumference) will be $$2(L + B)$$ units.

Rhombus

A rhombus is a quadrilateral whose all four sides have the same length.

Let the side be $$L$$ units.

Perimeter (circumference) will be $$4L$$ units.

Parallelogram

A parallelogram is a simple quadrilateral with two pairs of parallel sides. The opposite or facing sides of a parallelogram are of equal length and the opposite angles of a parallelogram are of equal measure.

Let the two Adjacent Sides be $$A$$ and $$B$$ units.

Perimeter (circumference) will be $$2(A + B)$$ units.

Ellipse

An ellipse is a plane curve surrounding two focal points, such that for all points on the curve, the sum of the two distances to the fixed point is a constant. The fixed point is called focal points of the ellipse.

Let the lengths of semi-major and semi-minor axes be $$a$$ and $$b$$ respectively,

Then circumference is given by

$$C\approx \pi \left(3*(a+b)-\sqrt{(3*a+b)*(a+3*b)}\right)$$

For calculating circumference of the various 2-D shapes using above circumference calculator, you have to just write the values in the given input boxes and press the calculate button, you will get the result.