Geometry: Polygons

Problem : Is the following figure a curve, closed curve, simple closed curve, polygon, or none of these?

Problem : Is the following figure a curve, closed curve, simple closed curve, polygon, or none of these?

Problem : Is the following figure a curve, closed curve, simple closed curve, polygon, or none of these?

Problem : Is the following figure a curve, closed curve, simple closed curve, polygon, or none of these?

Problem : Is the following figure a curve, closed curve, simple closed curve, polygon, or none of these?

Problem : If a polygon has 6 vertices, what is its general name?

Problem : If a closed curve consists entirely of segments, is it a polygon?