Π Pi (pie) Ρ Rho (roe) Σ Sigma (sig-mah) Τ Tau (taw) Υ Upsilon (youp-si-lon) Φ Phi (fie or fee) Χ Chi (kie) Ψ Psi (sigh) Ω Omega (o-meg-ah) ...

Getty Images The symbol for pi is also the 16th letter in the Greek alphabet "I feel very surprised," Ms Iwao, who has worked at Google for the past three years, said of her achievement.