July 2018 little math problem

[pier4r]

I should really collect all those little problems in one place :/

The problem should be solved ideally with pen and paper. Of course computing devices are allowed as last resort.

One has the numbers 1,2,3,4,5,6,7,8,9 and should arrange them in the following position without repetition.

Code:


a b c
    d
    e f g
        h
        i

The arrangement should be such that the four sides will have numbers that summed together, will produce the same value.

What are the arrangements? How many are there? Of course would be nice to know the way you picked to solve the problem.

Code:


you can give your answer

using spoilers like this




























RPL! RPL! RPL!