Question

What is the number pie

Answer 1

You meant pi, pi is a irrational number, but they use 3.14 for approximation, so that is your answer.

Hope this helped!

Nate

Answer 2

$\pi-\bold{pi}\\\\\pi\ \text{it's the ratio of a circle's circumference to its diameter}\\\\\pi=\dfrac{\text{circumference of a circle}}{\text{circle diameter}}\\\\\pi\ \text{it's irrarional number}\\\\\pi=3.14159265358979323846264338327...\\\\\text{Approximation of}\ \pi:\\\\\pi\approx3.14\\\\\pi\approx\dfrac{22}{7}\\\\\pi\approx\dfrac{355}{113}$

The number pi occurs when calculating the surface area or volume of the rotational solids.

Cylinder:

$S.A.=2\pi r^2+2\pi rH\\\\V=\pi r^2H$

Cone:

$S.A.=\pi r^2+\pi rl\\\\V=\dfrac{1}{3}\pi r^2H$

Sphere:

$S.A.=4\pi R^2\\\\V=\dfrac{4}{3}\pi R^3$

The number pi occurs when calculating the area and the circumference of a circle.

$C=\pi d=2\pi r\\\\A=\pi r^2$

It is also used to convert angle measure in degrees to radians.

$x^o=\dfrac{x\pi}{180}\ rad$