Download Lines and Angles Lesson Plan

Lines and Angles
Lesson Plan
Background Information
Objectives
At the end of the lines and
angles lesson, students will be
able to:
• Identify and apply the properties
of lines and angles.
• Understand the concept
of parallel, perpendicular,
complementary and
supplementary angles, vertical
angles, and parallel lines cut by
a transversal.
Geometry is used to describe the relationship of figures and objects to the space
around them. Lines are a series of points that continue in both directions. When
two lines lie on a two dimensional or flat surface, they are either parallel or they
intersect. Parallel lines never meet or intersect. They remain equal distance apart
no matter how far they are extended. Intersecting lines share a common point, or
vertex, where they cross, this forms angles.
This lesson should take approximately 1 hour and 15 minutes to complete, if all
components are utilized.
Video
Set up this first video by engaging students in a discussion of lines and angles in their
lives. The horizon, an aerial view of the city, the proportions and shape of a desk, chair
or door are the stuff of geometry. Geometry concepts require the understanding and
use of precise terms.
Show the video The Language of Geometry.
After watching the video, focus on these points:
• A point is a precise location in space that has no size.
• A line or line segment (ray) is a series of points, and forms the sides of an angle,
starting from a shared point or vertex.
• Angles are measured in degrees.
The next video, Symbols and Measures of Angles, explains how students may determine
the measurement of angles. Before watching the video, have learners discuss definitions of other terms, like vertical angles, supplementary angles, transversal, etc. Write
their definitions on the board, and then watch the video.
Show the video Symbols and Measures of Angles.
After watching the video, focus on these points:
• Angles are named by a letter or number at the vertex, or by three points, with the point in the middle always being the vertex.
• Opposite or vertical angles are congruent, meaning they have the same measure.
• A right angle measures exactly 90°. Right angles are formed by two intersecting perpendicular lines.
• An angle smaller than 90° is an acute angle.
• An angle larger than 90° is an obtuse angle.
• Angles formed by a line through the vertex of a right angle are called complementary Lines and Angles • 1
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angles. The sum of their angles is 90°.
• If the angle measures 180°, it is called a straight angle, or a straight line. Angles formed by intersecting that line are called supplementary angles. The sum of their angles is 180°.
• A transversal is a third line that intersects two parallel lines creating four angles at each intersection.
• Angles that are in the same position in each of the transversal intersections are called corresponding angles. They are congruent and have the same measure.
Worksheets/Practice
This worksheet packet from the GED Connection Mathematics workbook includes
problems that offer practice on the concepts presented in the videos.
Supplementary and Complementary Angles, p. 175, Skill Practice
Calculating the Measure of Angles, p. 177, Skill Practice
GED Practice, p. 186, problems 7 and 8
GED Practice, p. 187, problem 13
GED Practice, p. 188, problems 17, 18, and 21
GED Practice, p. 189, problem 34
Online Activities
For more resources and an overview of the 2002 GED® test, click
www.gedmathstrategies.com.
Test Tip:
•
Note how the concepts of complementary, supplementary, corresponding and vertical angles are used to determine the measurement of angles.
GED® and GED Testing Service® are registered trademarks of the American Council on Education. Used under license.
2 • Lines and Angles
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