+130514 If you take trig......you will run across a "formula" for the area of a sector of a circle
It's given by :
A = (1/2) r^2 (theta) where "theta" is the "central angle" of the sector measured in radians ....[ don't worry about the meaning of all these terms....... it isn't critical, here ]
The "central angle" measure of a sector formed by the whole circle = 2*pi radians
Thus, the area of the whole circle =
(1/2) r^2 [ 2 * pi] =
(1/2)(2)* pi * r^2 =
pi * r^2
Which is the familiar "formula" for the area of a circle......!!!!
Thus "pi" helps us find this area........
BTW.....before the "exact" value of "pi" was known [ not actually possible], mathematicians from India sometimes used the value sqrt(10) = about 3.16
The %error here is [3.16 - 3.14] / 3.14 = about 0 .636% [less than 1 percent !!! ]
