Learning goals: Teacher Facing Apply ratios and the Pythagorean Theorem to solve a problem involving the aspect ratio of screens or photos, and explain (orally) the reasoning. Describe (in writing and using other representations) characteristics of rectangles with the same aspect ratio or with different aspect ratios. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from 8.8 Pythagorean Theorem and Irrational Numbers, Grade 8.