# 1.4: The Theorem's Significance

Although the Babylonians may be the first to understand the concepts of the Pythagorean Theorem and the Pythagoreans were the first to explicitly prove it, Euclid of Alexandria, active around 300 BCE, was the man responsible for popularizing the theorem. Euclid, head of the department of mathematics at a school in Alexandria, took it upon himself to compile all knowledge about mathematics known at his point in history. The result was a book called *Elements*, which included two of Euclid’s own proofs of the Pythagorean Theorem.

The propagation of this theorem is significant because the theorem is applicable to a variety of fields and situations. Though the theorem is fundamentally geometric, it is useful in many branches of science and mathematics, and you are likely to encounter it often as you continue to study more advanced topics.

The Pythagorean Theorem, however, is also relevant to a variety of situations in everyday life. Architecture, for instance, employs the concepts behind the Pythagorean Theorem. Measuring and computing distances will also often involve using this theorem. Televisions, when advertised, are measured diagonally; for example, a television may be listed as “a 40-inch,” meaning that its diagonal is 40 inches long. The length of the television, the width of the television, and the Pythagorean Theorem were used to get this measurement.

Look out for ways that you can use this theorem in your everyday life—there may be more than you expected!