no, because 12+15 (two smaller sides) have to add up to more than the longer side, and they do not.

The two shorter sides call them a and b must be greater than the longest side c



c < a +b ,



The longest side above is 28 cm, the two shorter sides 12 cm and 15 cm only add to 27 cm.

Nope. because a triangle has to satisfy a^2+b^2=c^2





a=12, b=15, c=28





12^2+15^2=369





28^2 is not 369, so in other words, NO

No.