three-sided (adjective)

1. In Greek mythology, the trident wielded by Poseidon is a three-sided weapon.

2. In the cartoon show 'Steven Universe,' the character Garnet has a three-sided gemstone on her left hand.

3. In the novel 'The Three Musketeers,' the famous trio is always associated with their three-sided swords.

4. During the American Civil War, the flag of the Confederacy, also known as the 'Stars and Bars,' had a three-sided design.