There are many options:
1 + 1 + 1 ... (45 times)
1 + 1 + 1 ... (9 times) + 4 + 4 + 4 ... (9 times)
4 + 4 + 4 + 4 + 4 + 25
1 + 1 + 1 + 1 + 4 + 4 + 4 + 4 + 25
1 + 1 + 9 + 9 + 25
4 + 16 + 25
1 + 1 + 1 + 1 + 16 + 25
and what you were probably looking for but did not specifically ask for, 9 + 36
9 and 36
9 and 36
9 and 36
9 and 36
9 + 36 (3x3) + (6x6)
None. The ratio of two square numbers is itself a square number. 45 is not.
They are: 36+9 = 45
They are: 36+9 = 45.
They are: 36+9 = 45
9 + 36 = 32 + 62 = 45
32 + 62 = 9 + 36 = 45
Addition : 19 + 26 = 45 Subtraction : 71 - 26 = 45 Multiplication : 5 x 9 = 45 Division : 180 ÷ 4 = 45 Square root of 2025 = 45 Sum of the numbers : 1 to 9 = 45