 # Triangle Numbers: Follow the Sequence

In this worksheet, students recognise the sequence of triangles and add in missing numbers. Key stage:  KS 2

Curriculum topic:  Maths and Numerical Reasoning

Curriculum subtopic:  Sequences

Difficulty level:   ### QUESTION 1 of 10

Triangle numbers are formed by building triangle patterns as follows: You can draw these shapes or use addition to continue the sequence.

You should learn at least the first few triangle numbers....

1,  3,  6,  10,  15,  21,  28  .....

Is the following number a triangle number?

15

No

Yes

Is the following number a triangle number?

25

No

Yes

Is the following number a triangle number?

1

No

Yes

Is the following number a triangle number?

45

Yes

No

Is the following number a triangle number?

12

No

Yes

Is the following number a triangle number?

5

No

Yes

Is the following number a triangle number?

21

No

Yes

Is the following number a triangle number?

49

No

Yes

Is the following number a triangle number?

36

No

Yes

Is the following number a triangle number?

28

No

Yes

• Question 1

Is the following number a triangle number?

15

Yes
• Question 2

Is the following number a triangle number?

25

No
• Question 3

Is the following number a triangle number?

1

Yes
• Question 4

Is the following number a triangle number?

45

Yes
• Question 5

Is the following number a triangle number?

12

No
• Question 6

Is the following number a triangle number?

5

No
• Question 7

Is the following number a triangle number?

21

Yes
• Question 8

Is the following number a triangle number?

49

No
• Question 9

Is the following number a triangle number?

36

Yes
• Question 10

Is the following number a triangle number?

28

Yes
---- OR ----

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