In conclusion, do all of your students future math teachers a favor and do not teach them to "cross multiply and divide". Teach them to set the product of the diagonals equal to each other and then solve!
Here is your free content for this lesson!
Word Docs & PowerPoints
To gain access to our editable content Join the Geometry Teacher Community!
Here you will find hundreds of lessons, a community of teachers for support, and materials that are always up to date with the latest standards.
PDFs
71 Assignment  Ratios and Proportions ( FREE )
71 Bell Work (Members Only)
71 Lesson Plan  Ratios and Proportions (Members Only)
71 Guided Notes Student Edition  Ratios and Proportions (FREE)
71 Guided Notes Teacher Edition  Ratios and Proportions
71 Class Activity  Ratios and Proportions ( Members Only )
71 Online Activities  Ratios and Proportions (Members Only)
71 Exit Quiz  Ratios and Proportions (FREE)
71 Slide Show  Ratios and Proportions (FREE)
71 Video Lesson (Members Only)
Want access to the rest of the materials? To download the rest of the materials for this lesson and get updates via email when new lessons come out simply click the image below to Get All of Our Lessons!

Two Tips to Teach Volumes of Prisms and Cylinders

Pi Day Top 5 for Geometry Teachers

Hybrid Flipped Classroom Model

Valentine’s Day Math Activity – Classifying Quadrilaterals

Teaching Tessellations to Your Geometry Class

How to Teach Perimeter and Area of Similar Figures – in Jay Leno’s Garage

Christmas Math Worksheets

Introduction to Trigonometry

Ratios and Proportions – Bad Teacher!

How to Create a Jeopardy Game