triangle

/ˈtraɪˌæŋɡəl/
noun
  1. A flat shape with three straight sides and three angles.
    • A yield sign on the road is shaped like an upside-down triangle.
    • In geometry class, we learned how to calculate the area of a triangle.
    • The children drew a triangle on the paper and colored it blue.
  2. A musical instrument made of a metal rod bent into a triangle shape, played by striking it with a metal stick.
    • My little brother loves to bang on his toy triangle at home.
    • She played the triangle in the school orchestra during the concert.
    • The triangle made a clear, ringing sound when the musician hit it.
  3. A situation involving three people, especially a romantic relationship among three people.
    • The movie is about a love triangle between two brothers and a woman.
    • The novel explores the emotional tension of a romantic triangle.
    • Their friendship turned into a complicated triangle when feelings got involved.