Question

Does 21.6,28.8,36 equal a right triangle

Answer 1

21.6 < 28.8 < 36

if they are the lengths of the sides of a right triangle then:

$21.6^2+28.8^2=36^2\\\\L_s=466.56+829.44=1296\\\\R_s=1296\\\\L_s=R_s$

therefore it's the right triangle.