long time no blog liao...feel a little funny...well..todae...we had a 15-pupil class from 2-3.30...coz the rest went for maths olympiad...with only 16 ppl..Mrs Lee..taught us circles...and we did science presentation...not all the members of each group were there for the presentation..we did like a kind of conculsion and drew...after learning abt forces...well abt circles..it sounds pretty fun when mrs Lee explained...i was doing some research just now...let me tell u some stuff abt them..

What is pi ( )? Who first used pi? How do you find its value? What is it for? How many digits is it?

By definition, pi is the ratio of the circumference of a circle to its diameter. Pi is always the same number, no matter which circle you use to compute it.
For the sake of usefulness people often need to approximate pi. For many purposes you can use 3.14159, which is really pretty good, but if you want a better approximation you can use a computer to get it. Here's pi to many more digits: 3.14159265358979323846.
The area of a circle is pi times the square of the length of the radius, or "pi r squared":
A = pi*r^2

Well..this is only part of learning circles...more to go...
won't write anymore...gonna take my shower..will blog again