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# How to find area of shapes and how to find the volume of objects. (2d objects included)

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## How to find the area

This hub is to help with homework questions and to help anyone with questions about calculating area and volume of any shape or objects . Here I will speak on, how to find area of any shapes: circles, squares, triangles etc. and how to find the volume of objects, such as cubes, cuboids etc. Basically this hub will be giving you maths lessons online ,in the subject area mensuration.

## Firstly what is the area?

The area is the amount of space contained in a flat surface(2D object). The area can be calculated of any 2D surface like a floor, book cover,etc

How to find the area of a circle?

To find the area of a circle you multiply Π× r². Π stand for pi, it is 22/7. r is the radius, this is half of the diameter of a circle. If the diameter is 12cm, then the radius is 6cm. Therefore the area of a circle with a diameter of 12cm is: 22/7 × (6×6). 113.14cm². Remember area is always expressed in squared.

How to find the area of a square?

All the sides of a square are equal, therefore, square the length given to find the area of the square. For example, if given 5cm as the length, the area would be 5², the area equals 25cm².

How to find the area of a triangle?

To find the area of a triangle, you must know its base and its height. After that multiply the base by the height and divide the result by 2. For example, if the base is 5cm and the height is 10cm, then the area is 25cm²

How to find the area of a parallelogram?

A parallelogram has 4-sides, made of 2 pairs of equal, parallel lines. To find the area of a parallelogram multiply the base by the height.

How to find the area of a rhombus?

A rhombus is a 4-sided shape, whose sides are all equal. The area of a rhombus is half the product of the diagnals. The diagnals are the lines which join the opposite corners.

How to find the area of a trapezium?

A trapezium is a 4-sided shape with no parallel sides. To find the area of a trapezium multiply the lengths, divide the result by 2 and then multiply by the height.

How to find the area of composite figures?

Composite figures are figures which are made up of more than one shape. To find the area of a composite figure, you divide the shape given into simple shapes like triangles, rectangles etc. Find the areas of the individual shapes and then add up the areas.

## How to find the volume of objects.

The volume of a shape, is the amount of space that that 3D shape occupies or can hold. The volume of a glass is how much water that glass can hold.

To find the volume of most objects you multiply base by height, by width and the result is expressed in cube units (³).

## How to find the volume of a cube.(Remember all the edges of a cube are the same length)

To find the volume of a cube, remember to multiply the length by the width by the height.

To find the volume of a cuboid you follow the same process as you do to find the volume of a cube. Length by width by height, and remember your answer is always in units cubed. Units refer to metres, centimeters or millimeters.

## How to find the volume of prisms.

A prism is a 3 dimensional(3D) Sshape with ends that are similar, equal, and parallel. The two equal faces govern the name of the prism. For example if a prism has two triagular face, parallel to each other then it is called a triangular based prism.

Now how do we find the volume of a prism. Firstly you find the area of one of the parallel, sides then multiply that area by the height. Look at the diagram below for better understanding.

## Surface area

In some exams persons are asked to calculate the surface area of a 3D object. To do so you calculate the area of each face of the object, then you add all the areas of those faces together. The total you get is the surface area.

## Mensuration

I hope the little maths lesson online helps you with mensuration, maths can be a bit challenging but when you get the hang of it, it is really easy!

mathslover (author) from Barbados on August 12, 2014:

Mariyah Pana on August 09, 2014:

Hi any body here?

Z0e on May 06, 2013:

This site stinks

Hot stuff on April 17, 2013:

Great stuff but needs more 3d shapes I think

Abiel on April 07, 2013:

Very well but i want to find area and volume of right angled traingle with means half part of rectangle .. I think 1/2 *L*W but very nice.

sexy on November 21, 2012:

nice

alisa izumi on November 14, 2012:

kwl. info

Lucy on June 26, 2012:

Thank u.

mathslover (author) from Barbados on May 29, 2012:

thanks you

c saundiers on May 29, 2012:

very good

lolo on May 24, 2012:

LOL this was funny, idk how.

kamran memon on May 17, 2012:

very beautiful writer

mathslover (author) from Barbados on February 10, 2011:

Sorry this was not included. The formula for area of a regular decagon is given by A=2.5dt, where d is the distance between parrellel sides and t is the length of one edge.

umm on February 08, 2011:

how do you calculate a decagon