Question

If we combine two consecutive triangular numbers, we get?

(a) Rational Number

(b) Whole Number

(c) Perfect Square

(d) Prime Number

I got this question in exam.

My question is based upon Patterns in Squares topic in section Squares and Square Roots of Mathematics – Class 8

Answer 1

The correct choice is (c) Perfect Square

To elaborate: If we combine two consecutive triangular numbers, we get a square number, like

1 + 3 = 4 = 2^2 Hence, we get a perfect square when we add two consecutive triangular numbers. Here options other than Perfect Square are incorrect.