$$x^2 + 4x + 4 = (x + 2)^2 = 0$$ $$x + 2 = 0$$ $$x = -2$$
Using the Pythagorean theorem, we have: $$3^2 + 4^2 = 9 + 16 = 25 = 5^2$$ Therefore, the triangle is a right-angled triangle. stp mathematics 2a answers