# Catholic Encyclopedia (1913)/Thomas Ceva

Mathematician, born at Milan, 21 December, 1648; died there, 23 February, 1737. In 1663 he entered the Society of Jesus. He was a prolific writer on a variety of subjects, especially mathematics and poetry. He is known to-day only for the theorem in geometry which bears his name. Ceva's Theorem is: *three concurrent lines drawn through the vertices of a triangle divide the opposite sides so that the product of the three distance-ratios is equal to unity.* Ceva published this important proposition in 1678. It is the dual of the theorem of Menelaus.

Bibliotheque de la Compagnie de Jesus, II, 1015-1023.

J. McGivney.