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

Simple Closed Curve

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

Curve

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

Polygon

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

Closed Curve

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

Curve

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

Hexagon

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

Not necessarily. The curve must be a simple closed curve consisting entirely of line segments to be a polygon. A closed curve of all segments could still intersect itself.