Parallel Lines and Transversals in the Real World

This is one lesson in a larger Unit Plan that covers many properties of triangles and several other theorems.  It has proofs, real world problems, constructions, a unit project, assessments, and more.  In Lesson 5, “Is This Assignment on the Level?”, students produce a drawing illustrating the relationships of angles formed by transversals.  Includes a grading rubric.  The entire unit plan can be found here. This is a portion of a Unit Project, however, it could be used as a stand alone assignment as well. The "launch" is also an interactive review of vocabulary.

Standards & Objectives

Academic standards
Fluently add and subtract multi-digit whole numbers using the standard algorithm.
CLE 3108.1.1
Use mathematical language, symbols, definitions, proofs and counterexamples correctly and precisely in mathematical reasoning.
CLE 3108.1.2
Apply and adapt a variety of appropriate strategies to problem solving, including testing cases, estimation, and then checking induced errors and the...
CLE 3108.1.4
Move flexibly between multiple representations (contextual, physical written, verbal, iconic/pictorial, graphical, tabular, and symbolic), to solve problems, to...
CLE 3108.1.6
Employ reading and writing to recognize the major themes of mathematical processes, the historical development of mathematics, and the connections between...
CLE 3108.4.1
Develop the structures of geometry, such as lines, angles, planes, and planar figures, and explore their properties and relationships.
GLE 0206.2.1
Understand and use place value concepts to 1000.
GLE 0206.2.2
Understand and use the base-ten numeration system.
GLE 0206.2.3
Use efficient and accurate strategies to develop fluency with multi-digit addition and subtraction.
Fluently add and subtract within 1,000,000 using appropriate strategies and algorithms.
Alignment of this item to academic standards is based on recommendations from content creators, resource curators, and visitors to this website. It is the responsibility of each educator to verify that the materials are appropriate for your content area, aligned to current academic standards, and will be beneficial to your specific students.
Essential and guiding questions: 
  • How do special angles, parallel lines and transversals relate to real world situations?
  • What relationships can be determined by the angles formed by parallel lines cut by a transversal?
  • Why do the relationships of angles formed by parallel lines exist?

Lesson Variations

Blooms taxonomy level: 

Helpful Hints


  • Paper
  • Pencil
  • Markers
  • Colored pencils