Hi guys, first time posting here.

I've got an investigation question which I'm not sure on how to approach.

The question is: Consider the triangles whose side lengths are consecutive integers k, k+1, k+2, with k greater than or equal to 1.

(a)Comment on the nature of the triangle formed when k=1.

(b)Show that the triangle formed when k=2, is obtuse.

(c)Show that only a right triangle is formed when k=3.

The closest theory I've found that applies to the question is the Heronian Triangle:

Heronian Triangle -- from Wolfram MathWorld
I'm still not sure if it applies to my question or not. I'd appreciate any help which comes my way in solving the question posted above.

cem.