Answer:
Yes, it could be a triangle.
Step-by-step explanation:
If the Pythagorean Theorem is satisfied, then these three side lengths represent a right triangle:
21^2 + 28^2 = 36^2 => 1225 = 1296 FALSE; we don't have a right triangle here.
However, the sum 21 + 28 is greater than 36, so we could indeed construct a triangle from these 3 side lengths. It just wouldn't be a right triangle.
