The letters of the Greek alphabet are pronounced somewhat different to what you learned in maths.
Alpha,
beta, gamma, delta, epsilon, theta, iota, lambda, mu, pi, rho, sigma,
phi, psi and omega are the most commonly used Greek letters used in
maths, physics and engineering.
Pi (π)
is probably the most well known Greek letter, used in maths to
represent the ratio of the circumference to the diameter of a circle.
However it's pronounced "pee" in modern Greek, not "pie"