ACT Math
Lesson Plan
Triangle similarity criteria (AA, SAS, SSS) and proportional sides
Goals / Objectives
Find a missing side length in similar triangles by identifying corresponding sides, setting up the proportion and solving it, including in overlapping-triangle, parallel-line-cut and shadow setups
Establish that two triangles are similar by the AA, SAS or SSS criterion
State the definition of similar triangles and explain how similarity differs from congruence
Use the scale factor k to find perimeter ratios (k) and area ratios (k^2)
Standards
G 603. Apply properties of 30°-60°-90°, 45°-45°-90°, similar, and congruent triangles G 703. Use scale factors to determine the magnitude of a size change
Academic Vocabulary
Not in our source material
Enrichment
This lesson’s brief has no Differentiation
Accommodations
Not in our source material
Anticipatory Set / Bell Work
Modeling
Check for Understanding
This lesson’s brief has no Formative Assessment or Assessment Ideas
Guided Practice
Independent Practice
Homework
Pacing
This lesson’s brief has no Pacing