Triangular Number Calculator
Triangular Number Calculator
Triangular numbers get their name from the dot pattern they form — like bowling pins stacked into a triangle — and represent the sum of every whole number from 1 up to a chosen position. Enter a position n here and this calculator finds the nth triangular number instantly using the formula n(n+1)/2, instead of adding every number one by one. Triangular numbers also have a fun real-world interpretation: they count the number of handshakes possible among a group of people.
- The nth triangular number is the sum of all whole numbers from 1 to n, calculated instantly with the formula n(n+1)/2 instead of adding them one by one.
- Triangular numbers get their name from the dot pattern they form, like bowling pins arranged in a triangle: 1, 3, 6, 10, 15, 21, 28…
- Every triangular number is also the number of handshakes possible among n+1 people, since each new person shakes hands with everyone already there.
How do I calculate a triangular number?
Use the formula T(n) = n(n+1)/2, which sums every whole number from 1 to n without adding them one at a time.
What is the 10th triangular number?
T(10) = 10 × 11 / 2 = 55.
Triangular Number Calculator
Triangular numbers get their name from the dot pattern they form — like bowling pins stacked into a triangle — and represent the sum of every whole number from 1 up to a chosen position. Enter a position n here and this calculator finds the nth triangular number instantly using the formula n(n+1)/2, instead of adding every number one by one. Triangular numbers also have a fun real-world interpretation: they count the number of handshakes possible among a group of people.
- The nth triangular number is the sum of all whole numbers from 1 to n, calculated instantly with the formula n(n+1)/2 instead of adding them one by one.
- Triangular numbers get their name from the dot pattern they form, like bowling pins arranged in a triangle: 1, 3, 6, 10, 15, 21, 28…
- Every triangular number is also the number of handshakes possible among n+1 people, since each new person shakes hands with everyone already there.
How do I calculate a triangular number?
Use the formula T(n) = n(n+1)/2, which sums every whole number from 1 to n without adding them one at a time.
What is the 10th triangular number?
T(10) = 10 × 11 / 2 = 55.