triplet

Everyday

1. One of three children born to the same mother at the same time. tree →
2. A group or set of three things. tree →
3. (music) Three notes played in the time usually taken by two. tree →
4. (maths) A set of three numbers, such as a Pythagorean triplet like 3, 4, 5. tree →

In the lessons

In everyday life triplets are rare; people often find it hard to tell identical triplets apart. In maths, a triplet is a set of three numbers, and in geometry a Pythagorean triplet fits a right-angled triangle (3² + 4² = 5²). In music, triplets give a bouncy rhythm. Phrases: «a set of triplets», «identical triplets», «Pythagorean triplet».

Examples

• My neighbour has triplets — two boys and a girl. tree →
• The triplets all had red hair. tree →
• Identical triplets look almost the same. tree →
• In maths, 3, 4 and 5 make a Pythagorean triplet. tree →
• The music teacher showed us how to clap a triplet. tree →
• Mum bought three cakes, one for each triplet. tree →
• If the triplets are each 8, their ages add up to 24. tree →

Note

Countable. Triplets are three babies born together; twins are two; quadruplets («quads») are four. In maths problems, triplets are the same age, so multiply one age by 3 for the total. Triplets can be identical or not.