Year eight maths homework?

Question

My sister needs some help with her maths and i have no idea what the answers are so i need some help :)

This is the question:

The circumference of any circle divided by its diameter is a "special number" in mathematics.

a) What is the number called?

b) When was it discovered?

c) Find its approximate value.

I have a feeling it is pi (pie?) Lol???

Thanks! :)

Answer 1

C=pi *d= so C/d=pi

3.142857......

Discovered in ancient times somewhere between 1650 and 1900 B.C.

Answer 2

isnt it. Pi and 3.14.. also just search for the history..

Answer 3

yes, it is pi

approximately its value is 3,14

Answer 4

a) pi

b) no idea, you would have to research that a bit =/

c) 3.1415926535

Answer 5

The number you are referring to is called pi. pi in short equals 3.142 Nobody knows how pi was discovered.  We do know that pi has been known

for over  4000 years.

In 2000 BC the Babylonians used 3 1/4 as an approximation to pi, and the

Egyptians used 256/81.

It is very likely that people of thousands of years ago observed that

circles

of

different sizes were similar.  If you  measure the circumference of any

circle

and divide it by the diameter of the same circle, you will get the number

pi.

It is very easy to think that mathematicians of thousands of years ago would

have noticed that circumference divided by diameter would always give the

same number, regardless of the size of the circle.

In this sense we may say that pi was discovered by simply seeing that all

circles were similar.  Suppose you have two circles, the first a small

circle, and the second a bigger circle.  Then if you have a way to make the

smaller

circle bigger, you can turn it into exactly the bigger circle.

But once it was noticed that pi existed, how was it calculated.  How did the

ancients know how big pi was?

We think that they simply measured large circles.  That is why in ancient

times the most frequently approximations of pi have been 3, or 22/7 or 13/4.

None of these of course are exactly pi.  Pi cannot be written exactly except

by naming it.  When we write the name pi, we are specifying exactly the

value of pi.  When we write 3.14 we are specifying only an approximation to

pi.

It is approximately equal to 3.14159

Answer 6

a) PI

b) approximately 1900 BC

c) 3.14159, or 22/7

Answer 7

here is two parts....the number is called pie.....it is approximately 3.14, but i dont know who discovered it.  hope that helps!

Answer 8

Its either Pi or Radius.

Answer 9

to calculate the circumference = pi * diameter

if you divide it  by its diameter

= pi * diameter / diameter

the answer is pi

The history of pi you can find it in :

http://en.wikipedia.org/wiki/History_of_...

and its approximate value is 3.1416 or 3.14159 or 22/7

Here is a nice chronology of the computation of Pi:

20th century BC Egyptian Rhind Mathematical Papyrus (16/9)² = 3.160493...

19th century BC Babylonians 25/8 = 3.125

12th century BC Chinese 3

9th century BC Indian Shatapatha Brahmana 339/108=3.138888

434 BC Anaxagoras attempted to square the circle with compass and straightedge 223/71 < π < 22/7

c. 250 BC Archimedes 211875/67441 = 3.14163...

20 BC Vitruvius 25/8 = 3.125

130 Chang Hong √10 = 3.162277...

150 Ptolemy 377/120 = 3.141666...

250 Wang Fan 142/45 = 3.155555...

263 Liu h*i 3.141014

480 Zu Chongzhi 3.1415926 < π < 3.1415927

499 Aryabhata 62832 / 20000 = 3.1416

640 Brahmagupta √10 = 3.162277...

800 Al Khwarizmi 3.1416

1150 Bhaskara 3.14156

1220 Fibonacci 3.141818

Answer 10

a) Pi

b) 1900 BC, Babylonia (in what is now known as Iraq - ironic?)

c) 223/71 < π < 22/7

Answer 11

it is called pi

approximate value 22/7 or 3.14

the Egyptians over 4 thousands years ago

Answer 12

Yes, it's pi.  It's the greek letter which has the sound of our letter p.  It's written like two posts with a hat, so that's what you have to look for on a calculator.  Its approximate value is 3.14 or 22/7 and that sufficed for previous generations but nowadays with scientific calculators, children would be expected to get a more precise value.   It was discovered in 1650 B.C.