# Area Calculator

Circle

Triangle

Square

Rectangle

Rhombus

Parallelogram

Ellipse

## How To Use Area Calculator

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

Area is the quantity that expresses the extent of a 2-D shape in the plane.

Circle

A circle is a plane figure bounded by one curved line and such that all straight lines drawn from a certain point within it to the bounding line are equal. The bounding line is called its circumference and the point, its centre.

Let the Radius the Circle be $$R$$ units.

Area will be $$\pi R^2$$ square units.

The circle is the plane curve enclosing the maximum area for a given arc length.

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 Base and Height be $$B$$ and $$H$$ units respectively.

Area will be $$\dfrac{1}{2}BH$$ square 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.

Area will be $$L^2$$ square 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.

Area will be $$LB$$ square units.

When $$L=W$$, the rectangle is a square.

Rhombus

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

Let the two diagonals be $$P$$ and $$Q$$ units.

Area will be $$\dfrac{1}{2}\left(PQ\right)$$ square 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 Base and Height be $$B$$ and $$H$$ units respectively.

Area will be $$BH$$ square units.

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

and the Angle between the Adjacent Sides be $$\theta$$.

Area will be $$AB\sin\theta$$ square 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,

Area will be $$\pi ab$$ square units.

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