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1. Determine if each of the images below are a polygon or not.

This is a figure with 12 line segments. Each segment intersects two other segments at their endpoints.
Answer: Polygon

This is a figure with four line segments. One of the segments intersect only one side.
Answer: Not a polygon

This a closed figure with four line segments. Each segment intersects two segments at their endpoints. There are no segments on the inside of the figure.
Answer: Polygon

This is a closed figure with 4 curved sides; The figure looks like a rectangle. There are no segments inside the figure.
Answer: Not a polygon

This is a figure with two triangles intersecting at a point.
Answer: Not a polygon

2. Classify each of the polygons below as conves or concave.

This is a closed figure with four line segments. There are no segments on the inside of the figure.
Answer: convex

This is an arrow shaped figure with seven line segments as sides.
Answer: concave

This is a closed figure with six line segments. Two of the segments are bent towards the inside.
Answer: concave

This is a figure with 6 line segments. Each line segment intersects two other segments at their endpoints. There are no line segments on the iside of the figure.
Answer: convex

Practice Problem #3

The endpoints of this figure are called _____________.

This is a closed figure with seven sides. There are no line segments on the inside. The endpoints are A,B,C,D,E,F, and G.
Answer: vertices

Practice Problem #4

What best describes the figure below?

This is a 12-sided star shaped figure. Each segment has 1 congruence mark on them. 6 pairs of segments bend inward.
Answer: equilateral polygon

Practice Problem #5

A figure with 5 sides is a _________.
Answer: pentagon

Practice Problem #6

A nonagon has _______ sides.
Answer: 9

Practice Problem #7

All of the figures below are equilateral EXCEPT which one?

A. This is a 4-sided closed figure with four line segments. • One pair of sides have 1 congruence mark. • One pair of sides have 2 congruence marks. • All of the sides are straight line segments.

B. This is a four-sided figure; It has one tick mark on each side. It has four right angles.

C. This is a four-sided figure. It has one tick mark on each side.

D. This is a 4-sided closed figure with four line segments. • Four sides have 1 congruent tick mark on them. • All of the sides are straight line segments. • Two sides bend inward.

Answer: A This is a 4-sided closed figure with four line segments. • One pair of sides have 1 congruence mark. • One pair of sides have 2 congruence marks. • All of the sides are straight line segments.

Practice Problem #8

The figure below is a _____.

This is an image of a 18-sided star shaped figure.
Answer: 18-gon

Practice Problem #9

The figure below is a _____.

This is a dead end traffic sign.
Answer: quadrilateral

Practice Problem #10

What are the coordinates of the vertices of the polygon formed by the lines in the diagram?

A 4-sided polygon on a coordinate plane. The coordinates of the vertices are A(1,3) , B(-4,3), C(-2,1), and D(3,1). Four lines, y = 3, y = 1, y = -x + 4, and y = -x - 1, are drawn through the sides of the polygon.

Answer: (1,3),(−4,3),(−2,1), and (3,1)

Practice Problem #11

Find the coordinates of the vertices of the triangle formed by the lines:

  • y = −2x + 6,
  • y = x + 3, and
  • y = −x + 1.

Answer: (−1,2),(1,4), and (5,−4)

A 3-sided polygon on a coordinate plane. The coordinates of the vertices are (-1,2) , (1,4), C(5,-4). Three lines, y = -x + 1, y = -2x +6, and y = x + 3, are drawn through the sides of the polygon.