Tutor: Similar Triangles
Stuck on a proportion? Review the essentials below, then send a demo request describing where you got stuck.
1 Quick recap before you ask
Almost every question in this skill is answered by one of these lines.
AATwo pairs of congruent angles prove similarity.
SSS~All three side ratios match.
SAS~Two side ratios match with the included angles congruent.
The proportion△ABC ~ △DEF gives AB/DE = BC/EF = AC/DF. Cross-multiply to solve.
Order mattersMatch smallest to smallest, following the similarity statement.
Scale factorThe constant ratio of corresponding sides (ABC→DEF).
Shadowsheight/shadow is equal for both objects (AA from the sun’s rays).
Similar ≠ congruentSame shape, proportional sides — congruence is k = 1.
2 Ask a tutor
Describe your similarity problem and where you got stuck. A tutor will walk you through it.