Geometry, Teacher\'s Edition

• Review the following vocabulary prior to beginning the lesson.


• Congruent


• Perpendicular


• Complementary


• Supplementary


• Vertical angles


• Adjacent angles


• Linear pair

IV.AlternativeAssessment

• Walk around the room as students work.


• Collect the problems/diagrams that they created for a peer to solve.


• Use these as a classwork grade or to assess student understanding.

Perpendicular Transversals

I.SectionObjectives

• Identify the implications of perpendicular transversals on parallel lines.


• Identify the converse theorems involving perpendicular transversals and parallel lines.


• Understand and use the distance between parallel lines.

II.MultipleIntelligences

• Prior to teaching this lesson, provide students with another example. Request that they draw it out and then
  discover the 90◦angles for themselves. Then move on to the text.


• Having the students engage right away and draw conclusions about the material will help to reaffirm the new
  information in their minds.


• Assist students in completing as many constructions as they can throughout this lesson. Drawing out the
  examples will expand student understanding.


• Have students practice one or two more examples of finding the distance between straight parallel lines before
  moving on to slanted parallel lines.


• When you begin working on slanted parallel lines, list these steps on the board. Request that the students copy
  these steps into their notebooks.

a. Choose two points on one of the lines.

b. Use those points to find the slope of the line.

c. Take the slope and find the slope of the segment perpendicular to the line- the opposite of the reciprocal.

d. Select a point on the line and use the slope to draw a segment perpendicular to the line.

e. Take the coordinates of where this segment intersects both lines.

f. Use the distance formula and these coordinates to find the distance between the parallel lines.

Writing out the steps in this fashion assists students with verbally seeing something, writing it down, and talking
about it. Students will tend to remember the information better.

III.SpecialNeeds/Modifications

• Review the following vocabulary.

4.3. Parallel and Perpendicular Lines