posted by josh .
if the sides are 18 24 and 30 what kind of angle is it
note that it is just a scaled-up 3-4-5 triangle
You can check for a right angle using
30^2 = 18^2 + 24^2
if c^2 = a^2+b^2 it is a right angle
if c^2 < a^2+b^2, it is acute, otherwise obtuse