Question

Find the 10th 11th and 12th triangle number

Answer 1

Answer: 10th term: 55, 11th term: 66, 12th term: 78

Step-by-step explanation:

Formula = n (n+1)/2

Here, n stands for the particular term.

∴ The 10th triangle number = 10 * 11/2 = 5 * 11 = 55

∴ The 11th triangle number = 11 * 12/2 = 11 * 6 = 66

∴ The 12th triangle number = 12 * 13/2 = 6 * 13 = 78

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