Geometry, Teacher\'s Edition

5.5 Relationships within Triangles

Midsegments of a Triangle

I.SectionObjectives

• Identify the midsegment of a triangle.


• Apply the Midsegment Theorem to solve problems involving side lengths and midsegments of triangles.


• Use the Midsegment Theorem to solve problems involving variable side lengths and midsegments of triangles.

II.ProblemSolvingActivity-MidsegmentMystery

• Here is the problem.


• “Sari is working on a design for the roof of a dog house. Here is her design.”


• Figure05.01.01


• “Sari has forgotten her notes, but she knows thatxis equal to 7. What is her measurement foryifxis equal to
  7?”


• Use what you have learned about midsegments and triangles to help her work this out.


• Allow students time to work. Ask them to show all of their work when finished.

III.MeetingObjectives

• Students will identify the midsegment of a triangle.


• Students will apply the Midsegment Theorem to solve problems involving side lengths and midsegments.


• Students will demonstrate understanding by showing all of their work.

IV.NotesonAssessment

• Here is the solution to the problem.


• 
  

x= 7

3 x+ 5 =

1

2

y

3 ( 7 )+ 5 =

1

2

y

26 =

1

2

y

y= 52

• Be sure that student work is labeled and that students show all of their work.


• Provide feedback when necessary.

Chapter 5. Geometry TE - Problem Solving