Triangular Numbers Explained

The video tutorial explains triangular numbers, which are numbers that can form an equilateral triangle with dots. It describes the sequence of triangular numbers and highlights that each number in the sequence corresponds to the number of dots on each side of the triangle. The video also explains how to calculate triangular numbers by summing consecutive integers and provides practice questions for viewers to solve.

What is a triangular number?

• A number that is a multiple of six

• A number that represents objects forming an equilateral triangle

• A number that forms a square

• A number that can be divided by three

How many dots are on each side of the third triangular number?

• Two

• Three

• Five

• Four

What pattern is observed in the sequence of triangular numbers?

• Each number is a square number

• Each number is a prime number

• Each number is double the previous one

• Each triangle contains the previous one with an extra row

How is the 5th triangular number calculated?

• By dividing 25 by 5

• By adding 1, 2, 3, 4, and 5

• By multiplying 5 by 5

• By subtracting 5 from 10

What is the next step to find the 6th triangular number after knowing the 5th?

• Add 6 to the 5th triangular number

• Subtract 6 from the 5th triangular number

• Multiply the 5th number by 2

• Divide the 5th number by 6