It may look like the triangle is a right triangle, and if so it would be that m∠KML is 90 degrees. For the moment, let us assume that it is a right triangle, that ∠KML is 90.
That would mean that Pythagorean Theorem is applicable:
KL^2 = KM^2 + ML^2,
(19)^2 = (12)^2 + (16)^2,
361 = 144 + 256,
361 = 400,
361 ≠ 400,
(This means that Pythagorean Theorem is not applicable, and KLM is not a right triangle)
