Getting an Easy Formula for PI

PI is a number that represents the ratio of the circumference, to the diameter of a circle. While we are solving questions related with circle, most of the times we take π as 3.14 or 22/7 for the best approach and 3 to make the things easier. This instructable note will show you we can calculate the area or circumference of a circle without using PI and getting this formula is easy that high school students can understand easily.

I will use the Archimedes’ method, inscribed regular polygons in a circle. We will do it easier than Archimedes because we will use trigonometry.

To understand this project student must know :

1. Area and Circumference of the circle formulas.

2. Sum of interior angles of a polygon formula.

3. Properties of regular polygons.

3. On a right angled triangle how to get sine and cosine ratio.

You will see what area you were finding while calculating the area of a circle by taking PI as 3.14 or 3.

You can use this formula in any question instead of PI.

Teacher Notes

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Step 1: Starting With an Equilateral Triangle

Step 2: Regular Polygons

Step 3: From Regular Polygons to Circle

Step 4: Getting the Formula

Step 5: We Do Not Need PI

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