# Question: What Is The 12th Triangular Number?

## What are triangular numbers with examples?

The triangular number sequence is the representation of the numbers in the form of equilateral triangle arranged in a series or sequence.

These numbers are in a sequence of 1, 3, 6, 10, 15, 21, 28, 36, 45, and so on.

The numbers in the triangular pattern are represented by dots..

## Is 15 a triangular number?

This is the Triangular Number Sequence: 1, 3, 6, 10, 15, 21, 28, 36, 45, …

## Is 48 a triangular number?

There are infinitely many square triangular numbers; the first few are: 0, 1, 36, 1225, 41616, 1413721, 48024900, 1631432881, 55420693056, 1882672131025 (sequence A001110 in the OEIS)

## How do you find a triangular number?

About Triangular NumbersTriangular numbers are a pattern of numbers that form equilateral triangles.The formula for calculating the nth triangular number is: T = (n)(n + 1) / 2.

## Is 100 a triangular number?

The triangular numbers up to 100 are 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91 — so what’s next? Perfect Numbers These are the numbers which equal the sum of all of their smaller factors. They are few and far between — in fact, nobody knows how many there are.

## What is meant by Triangle?

A triangle is a polygon with three edges and three vertices. It is one of the basic shapes in geometry. A triangle with vertices A, B, and C is denoted . In Euclidean geometry, any three points, when non-collinear, determine a unique triangle and simultaneously, a unique plane (i.e. a two-dimensional Euclidean space).

## Why is 28 the perfect number?

A number is perfect if all of its factors, including 1 but excluding itself, perfectly add up to the number you began with. 6, for example, is perfect, because its factors — 3, 2, and 1 — all sum up to 6. 28 is perfect too: 14, 7, 4, 2, and 1 add up to 28.

## What is the 1000th triangular number?

Half of those dots were in the original triangle, so the 1000th triangular number is (1000 x 1001)/2 = 500500.

## What does triangular number mean?

: a number (such as 3, 6, 10, 15) representable by that many dots arranged in rows that form a triangle and that equals n(n+1)2 for some positive integer value of n.

## Is 72 a triangular number?

0, 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91, 105, 120, 136, 153, 171, 190, 210, 231, 253, 276, 300, 325, 351, 378, 406, 435, 465, 496, 528, 561, 595, 630, 666…

## How do you find tetrahedral numbers?

The formula for the n -th tetrahedral number is represented by the 3rd Rising Factorial divided by the 3rd Factorial. Tn=n(n+1)(n+2)6=n¯33! T n = n ( n + 1 ) ( n + 2 ) 6 = n 3 ¯ 3 ! Tetrahedral numbers are found in the fourth position either from left to right or right to left in Pascal’s triangle.

## What is the next square number after 16?

Informally: When you multiply an integer (a “whole” number, positive, negative or zero) times itself, the resulting product is called a square number, or a perfect square or simply “a square.” So, 0, 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, and so on, are all square numbers.

## Why 1 is a triangular number?

Triangular numbers have that name because, if drawn as dots they can form a triangle. But 1 is just a single dot, so it can’t be a triangular number, can it???

## What is the biggest triangular number?

666666 is the largest triangular number which you can form of the same digits (1, page 98). 666 is a Smith number.

## Is 0 a triangle number?

Therefore, 0 is usually regarded as a perfect square and cube. Other figurate numbers, like triangular numbers, sound firmly like geometric shapes and only as such. Since empty pictures do not suggest any actual geometric figure, 0 is usually not regarded as such a figurate number. The operative word here is “usually”.

## What are the triangular numbers from 1 to 100?

The triangular numbers up to 100 are 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91 — so what’s next? Perfect Numbers These are the numbers which equal the sum of all of their smaller factors. They are few and far between — in fact, nobody knows how many there are. Only 47 perfect numbers are currently known.