Thre are infinitely many solutions. The smalest set with two different triangular number adding to another is 6 + 15 = 21
36 and 45
Square numbers.
They are 24 and 15 which are composite numbers
21 and 22 add to 43
28 and 15
45
6 and 10 are triangular numbers that make 16.
the answer is of course 12
34
Thre are infinitely many solutions. The smalest set with two different triangular number adding to another is 6 + 15 = 21
There are an many triangular numbers that are also square numbers. Simply put, the sum of two consecutive triangular number equals a square number. Examples include 1 and 36.
1 and 43
The two numbers are 43 and 68. 43 + 68 = 111, while 68 - 43 = 25
36 and 45
Square numbers.
17 and 26