Answer:
4,5,6 are the three consecutive numbers. 16, 25 and 36 are their squares.
Explanation:
Let the three consecutive numbers be x, (x+1), (x+2)
Now, the squares of these three numbers are

Sum = 77
∴by the problem ,

{Taking 3 common }

{By factorization}

Therfore,

X can't be negetive
∴

The squares of the three consecutive numbers are 16, 25, 36
The three consecutive numbers whose sum is 77 are 4, 5, 6