triangulararithmetic

noun

UK /traɪˈæŋɡjʊlər əˈrɪθmətɪk/

US /traɪˈæŋɡjələr əˈrɪθmətɪk/

A kind of math that uses triangle shapes to help you add and count numbers.

In triangulararithmetic, the numbers 1, 3, 6, and 10 are special because they can be arranged as triangles.

SYNONYMS

triangular number theory triangle math figurate arithmetic polygonal number arithmetic

RELATED WORDS

triangular number sequence summation geometry pattern

OTHER MEANINGS

2. A method of arranging objects in triangular rows to count them quickly.

She used triangulararithmetic to count the chairs stacked in rows of one, two, and three.

3. The study of numbers that form equilateral triangles when drawn as dots.

The class explored triangulararithmetic by building dot triangles on paper.

4. A playful term for adding consecutive whole numbers together.

Adding 1 + 2 + 3 + 4 is a simple example of triangulararithmetic.