Ceva's theorem which is often attributed to the Italian mathematician Giovanni Ceva (d. 1734) was proved much earlier by Al-Mu'taman ibn Had.
Don Giovanni | Giovanni Pierluigi da Palestrina | Giovanni Bellini | Giovanni Riggi | Giovanni Boccaccio | Giovanni Battista Pergolesi | Giovanni Battista Tiepolo | Giovanni Battista Guarini | Giovanni | Giovanni Trapattoni | Giovanni "John the Eagle" Riggi | Giovanni Gabrieli | Giovanni Falcone | Villa San Giovanni | San Giovanni in Persiceto | Giovanni Verga | Giovanni van Bronckhorst | Giovanni Tamagno | Giovanni Pacini | Giovanni Battista Pescetti | Ceva | Giovanni Papini | Giovanni Hidalgo | Giovanni Domenico Cassini | Giovanni de' Medici | Giovanni Bottesini | Giovanni Battista Riccioli | Giovanni Zenatello | Giovanni Visconti | Giovanni Schiaparelli |