## Area And Circumference of a Circle : pi

**This site is now at www.breakingwave.co.nr**

This is a basic guide to using pi to find the area and circumference of a circle using pi. And also explores why pi makes our formulae work.

area =πr^{2}

circumference = 2πr or πd

where r = radius and d=diameter

**Area**

^{2}. This is simple enough to use, we multiply the radius by itself and then by pi.

**Does this make sense?**

^{2}. Of course the circle’s area is a bit smaller so we need to find the ratio between the areas of the square and circle. If we then times this value by four we have a magic constant to multiply r squared by to find the area of a circle (we times by four because we need the area of 4 quadrants and r squared gives us one).

**Circumference**

**Does this also make sense?**

**Conclusion**

perimeter of square to circumference of circle.

By David Woodford

## Pythagorases Theorm

Hello, this is my TREVOR Pythagoras blog about the GAME, however people keep looking at it because of the mathematician Pythagoras so ive decided to do a post on his triangle theorem

## The Theorem

“The square of the longest side (hypotenuse) is equal to the sum of the squares of the other two sides in a right angled triangle”

or mathematically

c^{2} = b^{2} + a^{2}

This is very useful for allot of applications.

## Applications of the theorem

There are many applications of Pythagoras besides simple triangles

eg)The difference between colors. Yes using pythag we can measure the “difference” between to colors as a number. This is how

- take you first and second color as a rgb number eg) red = 256 ,0,0 and a light shade of blue is 30, 100, 256.
- square the difference between the values for red, green and blue
- then find the square root of the sum of these values

Why does this work, because the hypotenuse of one triangle can be used as the base of another, and this triangle can be tilted by 90 degrees into the z plane the theorem can work in 3D :). We can then change the x,y and z axis to values for r,g,b. As pythag works in 3D we can calculate the distance between to colors(which are points in the rgb axis)

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