Jeff Gundrum, age 14, of Watertown, N.Y., for his question:

WHO WAS EUCLID?

Euclid was a Greek mathematician. He is often called the father of geometry.

More than 2,200 years ago, Euclid wrote a book called "The Elements." It is a book on elementary geometry and it was used as a textbook until about 1903.

"The Elements" consists of 13 books and its most important feature was the logical organization of what had been known earlier about ,geometry. It also contained chapters on geometrical algebra and number theory.

Little is known about Euclid's life. The place of his birth is uncertain.

Euclid lived during the reign of Ptolemy I. He founded the first school of mathematics in Alexandria. According to Proclus, a Greek philosopher who wrote about him 700 years after Euclid's death, the king asked Euclid if there were not an easier way to learn geometry than by studying "The Elements."

"There is no royal road to geometry," Euclid is said to have answered.

Euclid also wrote books on such subjects as optics and conic sections, but most of them have been lost.