1.C.VERTICES

2.D.DODECAGON

3.D.NUMBER OF SIDES

EXPLANATION:

1.A polygon is the union of three or more line segments whose endpoints meet. The segments are called the sides of the polygon. The points at which the segments meet (always the endpoints of the segments) are called VERTICES.

2.a dodecagon or 12-gon is any twelve-sided polygon.

3.Polygons are classified and described by the NUMBER OF SIDES, the kind of angles, and whether any of the sides are the same length (or congruent). ... They both are quadrilaterals (four sided polygons). Opposite sides are congruent for squares and rectangles. All four angles are right angles for both.

Answer:

1. What do you call the endpoints where the sides of a polygon meet?

A. angle

B. line segments

C. vertices

D. corner

2. What do you call a polygon with twelve sides?

A. heptagon B. nonagon

C. undecagon

D. dodecagon

3. Polygons are classified according to

A. line segments

B. corners

C. vertices

D. number of sides​

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Answers here:

1. B. line segments

2. D. dodecagon

3. D. number of sides​

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Hope it really helps you a lot</33