Singleton, Earl M. III          Daniel Hale Williams School     

Objectives 1) Students will be able to identify the names of angles formed when 
parallel lines are intersected by a transversal. 2) Students will be able to 
identify the measurement of angles formed when parallel lines are 
intersected by a transversal. 

Equipment and Materials 
Overhead Projectorr  One plastic overlayy  Three transparenciess 

Materials:  Crayonss  Four page worksheett 

Recommended Strategies:
Pass out the four page worksheet which contains the vocabulary and three other 
pages with parallel lines intersected by a transversal.  Begin the lesson by 
showing the parallel lines on the overhead projector.  "What are these lines?"  
"What are other examples of parallel lines in this room?"  Have a student define 
parallel lines.  Next, show the illustration of the parallel lines intersected 
by a transversal on the overhead projector.  "What is created when a transversal 
intersects the parallel line?" -- angles. Have the class turn to the second 
sheet and identify adjacent, supplementary, and straight angles -- all of which 
equal 180 degrees.  Have them color code the straight angle green and place a 
green arch over the straight angle to illustrate a semicircle.  Call on two 
students to come up.  Position them side by side, and ask the class the 
following question:  What would you call neighbors who, lived right next to each 
other on the same side of the street?  They would be next door neighbors and in 
math we call them adjacent angles.  They share a common ray and vertex. Next, 
have the class turn to the third page of the worksheet and label the top of the 
page corresponding angles.  Begin to identify congruent corresponding angles and 
color code each pair of corresponding angles a different color.  They will have 
four different pairs of corresponding angles -- each pair having a different 
color. Proceed to the fourth page and have the class label this page alternate 
exterior and alternate interior angles.  Again, have them color code each pair 
of angles.  Solicit the definition of interior and exterior.  Place a group of 
students in a circle and put one person in the middle of the circle.  The 
teacher should stand outside of the circle.  Ask questions about the 
relationship of the teacher to the person on the inside of the circle.  This 
activity will help reinforce the concept of interior/exterior relationship.  In 
order to further develop the concept of alternate, have the person on the inside 
of the circle alternate jumping up and down with the teacher.  Go to the board 
to illustrate alternate exterior and interior angles.  Lead them to discover 
that they are alternate exterior angles because they are on the opposite side of 
the transversal and on the outside of the parallel lines.  Continue by 
demonstrating that alternate interior angles are on the inside of the parallel 
lines and on alternate sides of the transversal. After reviewing all the terms, 
assign a measurement to one of the angles and have the class determine the 
measurement of the other angles and justify their answer.