English Reference
noun

triangle

n.
US /ˈtɹaɪˌæŋɡəɫ/ UK /tɹˈaɪæŋɡəl/ tri·an·gle UK spelling triangle's, triangle's

  1. 01 A1 Beginner Math

    a flat shape that has three straight sides and three corners.

    a polygon with three sides and three interior angles.

    Simple

    The children learned how to draw a square, a circle, and a triangle.

    In context

    The architect used a series of interlocking triangles to distribute the weight of the roof across the glass walls.

  2. 02 B1 Intermediate Music

    a musical instrument made of a metal bar bent into a triangle shape that you hit with a small metal stick.

    an idiophone percussion instrument consisting of a steel rod bent into a triangular shape, typically struck with a metal beater.

    Simple

    The boy waited for his turn to hit the triangle during the school concert.

    In context

    The composer added a single triangle stroke at the end of the movement to provide a bright, shimmering finish to the orchestral texture.

  3. 03 B2 Upper Intermediate

    a complicated situation where three people are involved in a romantic relationship with each other.

    a romantic relationship involving three people, often characterized by conflict or jealousy.

    Simple

    The movie is about a messy love triangle between two best friends and a new neighbor.

    In context

    The novel explores the psychological tension within a love triangle, focusing on how secrets eventually erode the trust between the three protagonists.

    love triangle
  4. 04 B2 Upper Intermediate

    a flat, plastic tool shaped like a triangle used for drawing straight lines and angles.

    a technical drawing instrument, often called a set square, used to provide a straightedge at a specific angle to a baseline.

    Simple

    You will need a ruler and a triangle to finish your geometry homework.

    In context

    The engineering student used a plastic triangle to ensure that every vertical line in the blueprint was perfectly perpendicular to the base.

    set square
  5. 05 B1 Intermediate Sport

    a frame used to arrange the balls into a triangle before starting a game of pool.

    a triangular frame used to rack the balls at the beginning of a game of billiards, pool, or snooker.

    Simple

    He placed the balls inside the triangle and made sure they were tight before the first shot.

    In context

    After the previous frame ended, the referee carefully positioned the triangle to reset the balls for the next round of the tournament.


From triangle; in North Carolina from being a triangular region.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Level A1 · Beginner
Frequency Frequent
Updated