In these lessons, we have compiled

Related Topics: More Geometry Lessons

The following table gives the formulas for the area and perimeter of square, rectangle. parallelogram, trapezoid (trapezium), triangle, rhombus, kite, regular polygon, circle, and ellipse. Scroll down the page if you want more examples and explanations for the areas and perimeters.

### Area of a Square

The formula for the area of a square is*s* × *s* = *s*^{2}, where *s* is the length of a side of the square.
### Area of Rectangle

### Area of Parallelogram

### Area of Trapezoid / Trapezium

Remember to use the height that is perpendicular to the base.

### Area of Triangle (given base and height)

### Area of Triangle (given 2 sides and an included angle)

We can find the area of the triangle using a formula that uses the sine function.

### Area of Triangle (given 3 sides)

### Area of an Equilateral Triangle

### Area of Rhombus (given the length of the diagonals)

### Area of Rhombus (given length of side and an angle)

What is the area of a rhombus that has two 120 degrees angle and a longer diagonal measuring 10 meters?

### Area of Kite (given the length of the diagonals)

**Area of Regular Polygon **

### Area of Circle

### Area of Sector

A sector is the portion of circle that is enclosed by two radii and an arc. The following video shows how to calculate the area of a sector in degrees.
### Area of Ellipse

You can use the free Mathway widget below to practice Algebra or other math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.

- a table of area formulas and perimeter formulas used to calculate the area and perimeter of two-dimensional geometrical shapes:
**square, rectangle. parallelogram, trapezoid (trapezium), triangle, rhombus, kite, regular polygon,**circle, and ellipse. - a more detailed explanation (in text and video) of each area formula.

Related Topics: More Geometry Lessons

The following table gives the formulas for the area and perimeter of square, rectangle. parallelogram, trapezoid (trapezium), triangle, rhombus, kite, regular polygon, circle, and ellipse. Scroll down the page if you want more examples and explanations for the areas and perimeters.

The area of a square is equal to the length of one side squared.

How to find the area of a square?Area of a square =

s^{2}

The formula for the area of a square is

A rectangle is a 4-sided polygon where all four of its angles are right angles. Normally, the longer side is called the length and the shorter side is called the width. If all the sides are of equal length then it will be called a square.

Area of rectangle = length × width

A =

lw

A parallelogram is a 4-sided polygon that has two sets of parallel sides. The opposite sides of a parallelogram are of equal length and the opposites angles are equal.

Area of parallelogram = base × perpendicular height

How to find the area of a rectangle, triangle and parallelogram, using base and height? Always use the height that is perpendicular to the base. Do not use the slant height.A =

bh

A trapeziod or trapezium is a 4-sided polygon that has at least one pair of parallel side. It is called a trapezoid in North America and a trapezium in Britain and other countries.

Area of trapezium = × (sum of two parallel sides) × height

How to find the area of a trapezoid?A = × (

a+b) ×h

Remember to use the height that is perpendicular to the base.

A triangle is a 3-sided polygon.

Area of triangle = × Base × Height

The following video shows an example of using the formula of half the product of the base and height to calculate the area of a triangle.A =

bh

How to find the area of a triangle given side-angle-side (SAS)?Area of triangle = ab sin C

We can find the area of the triangle using a formula that uses the sine function.

Area of triangle =

This is also called the Heron's Formula

How to find the area of a triangle given the 3 sides? The following video shows how to use the Heron's Formula.To find the area of an equilateral triangle, we can use the following formula:

The area of an equilateral triangle (with all sides congruent) is equal to

where *s* is the length of any side of the triangle

A rhombus is a 4-sided polygon that has 4 equal sides. The diagonals of a rhombus bisects each other at right angles.

Area of rhombus = product of diagonals

Area of rhombus = *a*^{2} sin *c* where *a* is the length of the side and *c* is any interior angle.

(You can use any interior angle because either they are equal or they are supplementary and supplementary angles have the same sine.)

What is the area of a rhombus that has two 120 degrees angle and a longer diagonal measuring 10 meters?

A kite is a 4-sided polygon that has two distinct pairs of adjacent sides that are congruent.. The diagonals of a kite bisects each other at right angles.

Area of a kite uses the same formula as the area of a rhombus

Area of kite = product of diagonals

A regular polygon is a polygon where all the sides are the same length and all the angles are equal.

The apothem of a regular polygon is a line segment from the centre of the polygon to the midpoint of one of its sides.

Area of regular polygon = where *p* is the perimeter and *a * is the apothem.

A circles is a shape consisting of those points in a plane which are at a constant distance, called the radius, from a fixed point, called the center.

Area of circle = × (radius)^{2}

A = *r*^{2}

An ellipse is a curved line forming a closed loop, where the sum of the distances from two points (foci) to every point on the line is constant. It looks like a circle that has bee squashed into an oval.

If 2*a* and 2*b* are the lengths of the major and minor axes of the ellipse, then the area of the ellipse is π*ab*.

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