Given that a is the longest side length in the triangle, which of the following inequalities would make the triangle above an obtuse triangle? A. a² +6² <c²
B. a² +6² >c²
C. b² + c² <a²
D. b^2 + c^2 >a^2

hello from mrbilldoesmath!

answer:   x (x+6)^2, choice b

discussion:

factor x out of the equation:

x^3 + 12x^2 + 36x = x (x^2 + 12x + 36).

note that 6+6 = 12 and 6*6 = 36 so the above factors into:

x (x+6)^2

which is choice b

you,

mrb