Archimedes' constant $\pi$

The constant $\pi$ represents the area of the unit circle, the half-period of trigonometric functions, and many other things in mathematics.

Symbol
$\pi$
Formulae
$3.141592653589793$
Used in
$A_{a_{1}}$
$A_{fluid}$
$\beta_{X}$
$\Delta \theta_{kp}$
$\gamma_{a}$
$\omega$
$\theta_{gas}$
Gas temperature [$^{\circ}$C]
$U_{partially}$
$U_{wall}$
OHTC of pipe wall [W/(K.m$^2$)]
$V_{comp}$
Gas volume [m$^3$]
$W_{tube}$
$X_{0}$
$X_{c}$
$X_{S1}$
Reactance section 1 [$\Omega$/m]
$X_{S2}$
Reactance section 2 [$\Omega$/m]
$X_{S3}$
Reactance section 3 [$\Omega$/m]