The English prefix **tri-**, derived from both Latin and Greek roots, means “three.” Let’s do a “**tri**ple double” by looking at these two root words that mean “three!”

Math, as one might expect, often uses number prefixes, and the prefix **tri-** meaning “three” is no exception. A **tri**angle is a figure with “three” angles. The branch of mathematics which primarily studies **tri**angles is **tri**gonometry, or the measurement of figures containing “three” angles. The number **tri**llion, bandied about so much these days in the news, is the number 1000 times itself another “three” times. If you **tri**ple a **tri**llion, you make it “three” times bigger!

The Ironman **tri**athlon consists of “three” grueling athletic contests: 2.4 miles of swimming, 112 miles of cycling, and a full marathon distance for running. Athletes participating in the Ironman could not do well without their **tri**ceps, or that muscle which attaches in “three” places on the back of the upper arm, opposite the biceps. Rest assured that these elite **tri**athletes do not use **tri**cycles, or a bicycle with “three” wheels, in the cycling part of the contest!

The humanities as well love using the prefix **tri-**, or “three.” A **tri**o is a musical group that consists of “three” singers. A **tri**ad can also refer to any group of “three.” The god Poseidon wielded the powerful **tri**dent, or mighty spear that had “three” prongs. A **tri**logy consists of a series of “three” books, such as in the series *The Lord of the Rings*.

And last but not least, a dilemma perhaps doesn’t seem so bad when you have a **tri**lemma on your hands instead, or a very difficult choice between “three” options instead of just two!

Now you will no longer have to “try” to figure out what the English prefix **tri-** means, perhaps **tri**pling your time saved by not having to look in the dictionary for all those once “trying” **tri-** words!

**triangle**: geometrical figure with ‘3’ angles**trigonometry**: the mathematical study of figure with ‘3’ angles**trillion**: the number 1000 multiplied by itself another ‘3’ times**triple**: to multiply by ‘3’**triathlon**: an athletic contest featuring ‘3’ primary events**triceps**: a muscle with ‘3’ heads, or places where it attaches**tricycle**: a bicycle with ‘3’ wheels**trio**: a group of ‘3’ singers**triad**: any group of ‘3’**trident**: a spear with ‘3’ prongs**trilogy**: a series which consists of ‘3’ books**trilemma**: a choice you have to make between ‘3’ equally viable options