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# Geometry/Area and Perimeter

Question

Area and parimeter
QUESTION: Hello sir

Thankyou sir for your clear explaination of that garden question. I understood sir. There was a misunderstanding in that question . Now it was clear and i am very happy.

Sir but ihave another question --: A flooring tile has the shape of parallelogram whose base is 24 cm and the corresponding height is 10 cm . How many such tiles are required to cover a floor of area 1080m square. In this why do we divide area of one by area of floor .

Commonly i want to ask why do we calculate area why we can't calculate parimeter. bEcause when we see the tiles there is a line called boundry  and what we do by taking the area of only inside the boundry.The boundry is there then we are not taking the area of whole figure. then why. Sir there is an attachment please see it. It would be more clear.

Let us be clear on definitions.  The area is the two-dimensional region that lies within the boundary.  The perimeter is the length of the boundary.

The boundary delineates what is the figure.  When you calculate the area, you calculate the area of the whole figure.
To quote your question, "what we do by taking the area of only inside the boundry".  What other area is there?  Area outside the boundary?

If you think some area gets missed, please ask a follow-up and provide an example or a diagram.

Whenever you want to cover the area with tiles or paint or some such, you need to calculate area.  When you want to surround the area with a fence, you need to calculate perimeter.

Hope this helps!
Azeem

---------- FOLLOW-UP ----------

QUESTION: Hello sir

Thankyou sir. I understood sir

Sir but one part of my question is missing sir that is

A flooring tile has a shape of parallelogram ehose base is 24cm and coresseponding height is 10 cm.How many tiles are required to cover a floor of area 1080cm sqaure.

In this first step we find the area of one tile = bxh ie 24x10= 240.

Second step = We divide 240by1080cmsquare. This step only confusing. why cant multilpy 240x1080. Why we have to divide.?

Sir pease expain this aso clearly

Hi,

The entire area is 1080.  The area of one tile is 240.  To determine the number of tiles needed, you must divide the entire area by the area of one tile: 1080/240.

Think of it this way.  The more tiles you have, the more area you will cover.

(# of tiles) x (area of one tile) = (total area)

You can rearrange this equation to solve for the number of tiles.

(# of tiles) = (total area) / (area of one tile)

Another way to see this is to look at the units.  You are looking for a number, you don't want any cm or cm squared in your answer.

(1080 cm squared)/(240 cm squared) = 4.5

Note that if you multiplied, you would get cm^4, which does not make sense in this situation.

Azeem

Geometry

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#### Azeem Hussain

##### Expertise

I welcome your questions on algebra, 2D and 3D geometry, parabolic functions and conic sections, and any other mathematical queries you may have.

##### Experience

4 years as a drop-in and by-appointment tutor at Champlain College. Private tutor for dozens of clients over the past 8 years.

Publications
CALPHAD: Computer Coupling of Phase Diagrams and Thermochemistry

Education/Credentials
Bachelor of Science, Major Mathematics and Major Economics, McGill University, 2014. Diploma of Collegiate Studies; Pure and Applied Science, Champlain College Saint-Lambert, 2010.