Geometry · Similarity & Right Triangles
Similar Figures
HSG-SRT.A.2
Definition
Figures with the same shape, having congruent angles and proportional side lengths.
Teach it
Where it is taught, with guided notes, practice, homework, an exit ticket and an interactive Teacher Deck.
Examples
- Triangle ABC ~ Triangle DEF with side ratios 6:3 = 8:4 = 10:5 = 2, so the figures are similar.
- Two rectangles are similar if their side lengths share the same ratio, like 4:2 and 8:4.
Key rule
Similar figures always have congruent angles and proportional sides.
Memory hook
Same shape, different size — angles match, sides scale.