AHSME 1960 Problem 13

The polygon(s) formed by $y=3x+2, y=-3x+2$, and $y=-2$, is (are): $\textbf{(A) }\text{An equilateral triangle} \textbf{(B) }\text{an isosceles triangle} \textbf{(C) }\text{a right triangle} \\ \textbf{(D) }\text{a triangle and a trapezoid} \textbf{(E) }\text{a quadrilateral}$