The letter B probably started as a pictogram of the floorplan of a house in Egyptian hieroglyphs or the Proto-semitic alphabet.

By 1500 BC, the Phoenician alphabet's letter had a linear form that served as the basis for all later, which appeared in both the angular and more rounded forms. Its name must have corresponded closely to the Hebrew beth.

When the Ancient Greeks adopted the alphabet, they changed its name to beta and turned the letter upside-down and later added a second loop. In earlier Greek inscriptions, the letter faces to the left, but in the Greek alphabet of later times it faces to the right, although there continued to be variations between pointed and rounded loops.

The Etruscans brought the Greek alphabet to what is now Italy and left the letter unchanged. The Romans later adopted the Etruscan alphabet to write Latin, and the resulting letter, with rounded loops, has been preserved in the modern Latin alphabet used to write many languages, including English.

Thanks for the review!

why thank you! :D