Question

By adding 2 consecutive triangular numbers, we get ______ .

• A. zero
• B. triangle numbers
• C. square numbers
• D. line numbers

Answer 1

The correct option is C square numbers

Adding the consecutive triangular numbers we get,
3+6=9
6+10=16
10+15 = 25
It is clear that the numbers 4,9,16 are square numbers as,
$2^2$=4
$3^2$=9
$4^2$=16
$5^2$=25