| A | B |
|---|
| Tri (G) Tres (L) | "three" |
| trilogy | a group of thre literay or musical works that have a related theme |
| trisect | to divide into three parts |
| triumvirate | a group of three, esp. in authority |
| Vir (L) | "man" |
| Quartus, quatuor (L) | "four" or "fourth" |
| quadrant (1) | a quarter of a circle or of its circumference |
| quadrant (2) | an early machine for measuring altitudes |
| quandrant (3) | any of the four parts of an area divided by perpendicular lines |
| quartet | a musical composition for four voices or instruments |
| quatrain | a stanza or group of four lines of poetry |
| Decem (L) | "ten" |
| decimate | to destroy a large part of |
| decathlon | an athletic contest in which each contestant takes part in ten events |
| Centum (L) | "hundred" |
| bicentennial | a two-hundredth anniversary |
| centenary | pertaining to a 100-year period |
| centigrade | referring to a thermometer scale of 100 degrees |
