Two-Dimensional Figures Line Segment

Name______Date______

Two-Dimensional Figures

Line segment: ______

A line segment is a part of a line. It has a beginning and an end, and it is straight.

Angle:

An angle is formed by two lines or two line segments that cross each other. The point where these two line segments cross is called a vertex. All angles have a vertex.

Triangle:

A triangle is a figure with three sides and three angles. All these figures are triangles.

Right angle:

A right angle is an angle that is formed by two perpendicular lines crossing. Rectangles and squares and rectangles have four right angles.

Closed Figures Closed figures are formed of lines or line segments. Closed figures have no openings.

Rectangle:

A rectangle is a figure with four sides and four right angles.

Square:

A square has four right angles, like a rectangle. Unlike a rectangle, a square has four equal sides.

Circle: *

A circle is a round figure. All the points on the edge of a circle are the same distance from the center.

Polygon:

A polygon is closed figure bounded by straight sides.

Triangles, rectangles, and squares are polygons.

Other polygons:

Pentagon (5 sides) Hexagon (six sides) Octagon (8 sides)

Some figures are NOT polygons.

A circle is not a polygon, because it does not have straight sides.

This figure is not a polygon, because it has a rounded side.

Polygons

1. Draw a polygon with four sides.

2. Draw a polygon with three sides.

3. Draw a polygon with four right angles.

4. Which figure is NOT a polygon?

a. n b. c. d.

5. Which of these figures is not a polygon?

a. b. c. d.

6. This is not a polygon. Explain why.

______

Angles

An angle is formed when two line segments intersect. The point where the two line segments intersect is called the vertex. Vertices are the term for more than one vertex.

vertex vertex

Polygons have angles.

1. How many angles does this triangle have? ____ How many vertices? ______

2. How many angles does this rectangle have? _____ How many vertices? ______

3. How many angles does this pentagon have? ____ How many vertices? ______

4. Do you see a pattern? Explain. ______

Squares and rectangles have square corners. These square corners are called right angles.

5. Look around the room. List some of the right angles you see. ______

Squares and Rectangles

A rectangle has four sides, four vertices and four right angles. A square is a rectangle with four equal sides.

This is a rectangle. This is a square.

Look at the picture below. Identify the rectangles. Put an R on the rectangles. Put an S on the squares.

Look around the room. List the objects that are rectangles or squares.

Rectangles Squares

Look at the design. With a colored pencil, put a small square at each right angle.

Connect the terms with the matching figure.

1. square a.

2. vertex b.

3. rectangle c.

d. 4. pentagon

e. 5. triangle

f. 6. hexagon

g. 7. circle

h. 8. right angle

i. 9. line segment

10. octagon j.

Two-Dimensional Figures

T H G I A R T S V G A E U O O G N R S Y I F O S V Y T G V D T O E Q E R A U Q S N E E E B X G C M L D G N C U N R M B Z P A T F G A I G D I T I Y I I A X A K N E U S L E R U G I F D E N U A S S P X L S C T Y O R H G Y I T E E J C F O L W N W S L Y R N F P N R L W L E L S A E Q T T O R J I O Z P C P S E P A H S E G K C L O C Q P A N G L E T E M Y I O J U W R E O D A N U K I O L Y J Y N Y N V Y E R F Q O N E O N R T N E Q C X Z J K P R N G P L Y D

ANGLE FIGURE OPEN SIDES CENTER GEOMETRY PENTAGON SQUARE CIRCLE HEXAGON POLYGON STRAIGHT CIRCLE LINE RECTANGLE TRIANGLE CLOSED LINE SEGMENT SHAPE VERTEX

Answers

Page 4 1. answers will vary 2. answers will vary 3. answers will vary 4. b 5. c 6. This figure is not a polygon because it has a curved edge. Polygons have straight sides.

Page 5 1. 3 angles, 3 vertices 2. 4 angles, 4 vertices 3. 5 angles, 5 vertices 4. The number of angles and the number of vertices for a figure are the same. 5. answers will vary

Page 6 Assessment is visual

Page 7

1. c 2. d 3. f 4. i 5. h 6. e 7. a 8. j 9. b 10. g