what is an apex

An apex is the highest point or vertex of a shape or object. It can also refer to the point of sharpest curvature in a path, such as that followed by a turning vehicle. The term is typically used to refer to the vertex opposite from some "base" in geometry). For example, in an isosceles triangle, the apex is the vertex where the two sides of equal length meet, opposite the unequal third side). In a pyramid or cone, the apex is the vertex at the "top" opposite the base). The word "apex" is derived from the Latin for summit, peak, tip, top, extreme end).