Page 180 - New Medley 5 Semester 2

2 × 3
2nd term = 3 = 1 + 2 =
2

3 × 4
3rd term = 6 = 1 + 2 + 3 =
2

4 × 5
4th term = 10 = 1 + 2 + 3 + 4 =
2
5 × 6
5th term = 15 = 1 + 2 + 3 + 4 + 5 =
2

.............................................................................

.............................................................................

Thus, we can compute any term of the pattern by following the above rule.
For example,
×
89
8th triangular number = = 36
2
×
15 16
and 15th triangular number = = 120
2
Square Numbers

...

1 4 9 16 25 ...

(1 × 1) (2 × 2) (3 × 3) (4 × 4) (5 × 5) ...

We see that each term of the above pattern is a product obtained by

multiplying a natural number with itself. Therefore, we can find any term

of the pattern using this property.

Now, let us consider the pattern in a different way.

...
4 = 1 + 3 9 = 3 + 6 16 = 6 + 10 ...

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