Find the discriminat of each quadratic equation then state the number and type of solutions

Hello : 
the discriminat of each quadratic equation : ax²+bx+c=0 (a ≠ 0) is :
Δ = b² -4ac
1 )  Δ > 0  the equation has two reals solutions : x =  (-b±√Δ)/2a
2 ) Δ = 0 : one solution : x = -b/2a
3 ) Δ < 0 : no reals solutions

Answer d; a supplementary angle = 180°, so if that angle = 150°, y would = 30°.

Iagree that is the answer to the question