For a triangle with sides a,b,c, use the cosine formula
since on both triangles you have, a=d and b=e, then you just have to look at the .
Since is a decreasing function on , if where x is an angle (and they're both contained in ) then .
So for your triangles, the triangle with the larger angle will result in a smaller cos value and hence will be larger.
I don't think this is clear what I've written so reply back if not...