Final answer:
The 16th Greek letter that is also a math term is Pi (π), which represents the ratio of a circle's circumference to its diameter, approximately 3.14.
Step-by-step explanation:
The term that is both a math term and the 16th letter of the Greek alphabet is Pi (π). Pi is utilized to represent the mathematical constant that is the ratio of a circle's circumference to its diameter. This value is approximately 3.14, but it is an irrational number that continues infinitely without a repeating pattern. The symbol for Pi (π) has become iconic in mathematics and is celebrated around the world on Pi Day, March 14th (3/14).