Final answer:
Open shapes are those where the lines or curves do not meet or are not connected, unlike triangular, closed, and circular shapes which all enclose space fully and form a complete loop. The correct option is B.
Step-by-step explanation:
Among the given options, the shapes where the straight lines or curves do not meet or are not connected are open shapes. A shape is defined as an enclosed area, but an open shape does not fully enclose a space, meaning the start and end points are not the same, which is why these shapes do not form a complete loop.
In contrast, triangular shapes, closed shapes, and circular shapes all have lines or curves that connect back to their starting points, forming a closed loop.
An example of an open shape would be a simple arc or a line segment, where you have distinct start and end points. To illustrate, if you draw a 'C' shape on paper, this is an open shape because if you were to travel along the edge, you would not end up back where you started without retracing your steps. Comparatively, if you draw a circle, you will end up back at your starting point, which makes it a closed shape.
An example from conic sections is an ellipse, which is a closed curve and is categorized as a closed shape, not an open one, as previously mentioned in this context. The ellipse, along with the circle, parabola, and hyperbola, are all formed by the intersection of a plane with a cone and are well-known conic sections.