(5,12,13) is a right triangle and can be constructed. All the others do not satisfy the triangle inequality, i.e. the sum of two short sides must exceed the long side in order for the triangle to be constructed. Examples: 2+11<15, so no 3+7<11, so no 4+8<15, so no but 5+12>13 so yes, it can be constructed.
Perpendicular Lines have OPPOSITE MULTIPLICATIVE INVERSE <em>RATE OF CHANGES</em> [<em>SLOPES</em>], whereas Parallel Lines have SIMILAR <em>RATE OF CHANGES</em> [SLOPES].