Gamma

Αα Alpha
Ββ Beta
Γγ Gamma
Δδ Delta
Εε Epsilon
Ζζ Zeta
Ηη Eta
Θθ Theta
Ιι Iota
Κκ Kappa
Λλ Lambda
Μμ Mu
Νν Nu
Ξξ Xi
Οο Omicron
Ππ Pi
Ρρ Rho
Σσς Sigma
Ττ Tau
Υυ Upsilon
Φφ Phi
Χχ Chi
Ψψ Psi
Ωω Omega

Since I NBTD, and thought of the Greek symbol that we often use, in Maths or Physics.

So here they are, got the above from wikipedia.

Some are common to most people, some are not.

i guess [Pi] is the most famous one, in both Maths and Physics.

Oh ya, there's another thing, an upside down Delta,

∇, this is the Nabla symbol.

Came across this when I was at the Maths course, the Backward Difference.

It gots its symbol from a harp, with a similar shape.

What's a harp?

The angel's musical instrument.

Still no idea?

Click here.

Now you know.