This is a tough nut but not hard to crack so how about having a go and sending in your solution. This should help you to get started.
There are 6 vertices and 5 edges. Let's suppose
the magic constant is
and this is the same at
each vertex. The total of all the numbers 1 + 2
+ ... + 11 = 66 but the numbers on the edges,
are counted twice. So
So
is a multiple of 6 and it is at
least
so it must be 18 or more.
Hence
and
.
Now you need to consider several cases for different values of
, starting with
, and for each value of
you have information about the sum of the numbers on the five edges. Also for the feet you have to find 4 pairs of numbers adding up to
.