Final answer:
The fraternity symbol with Pi Kappa Phi's letters on a bell is known as the Bell of Friendship, used to denote fraternity fellowship.
Step-by-step explanation:
The fraternity symbol with Pi Kappa Phi's letters written on a bell is known as the Bell of Friendship. It's an emblem used by the Pi Kappa Phi fraternity to represent a sense of fellowship among its members. The Greek alphabet is utilized by various Greek-letter organizations, like fraternities and sororities, to create distinctive symbols and identities. The letter pi (π) is a Greek letter that in mathematics represents the constant ratio of a circle's circumference to its diameter, an infinite number often approximated as 3.14. In the context of the fraternity, however, the symbols pi (π), kappa (κ), and phi (φ) are used to signify the fraternity's name rather than mathematical concepts.