Paul Ingrisano has trademarked the symbol for Pi and has nearly-exclusive rights to "I<3," the ... (with Ingrisano’s trademarked “π.” logo in the corner). These designs are as witless as ...

In January, the U.S. Patent and Trademark Office gave Ingrisano a trademark on the symbol π.—pi followed by a period—a design Ingrisano uses on T-shirts sold at some brick-and-mortar stores.

To find the symbol for pi and have an easier time typing it on your iPhone, you'd have to add the Greek keyboard to your mobile device. Here's how: Launch the Settings app.

Pi Approximation Day celebrates the pi symbol (π) and its importance to mathematics. The symbol is a Greek letter, and it is used in mathematics to represent the ratio of the circumference of a ...