Final answer:
Leonardo Pisano is best known by the nickname Leonardo Fibonacci, the mathematician famous for introducing the Fibonacci sequence to the Western world.
Step-by-step explanation:
Leonardo Pisano is best known by his nickname, b. Leonardo Fibonacci. He was an Italian mathematician born in the 12th century, famed for the introduction of the Fibonacci sequence to Western mathematics, although these numbers had already been described earlier in Indian mathematics. The sequence, where each number is the sum of the two preceding ones, appears in many different areas of mathematics and science.
Leonardo da Vinci, on the other hand, was a polymath of the Renaissance period known for his paintings like the Mona Lisa and The Last Supper, as well as his contributions to various fields including engineering and anatomy.
Leonardo Fibonacci made a significant impact on mathematics and is not to be confused with Leonardo da Vinci, who was also an exceptional figure but in different areas of the Renaissance humanism movement.