Back to Triangle similarity criteria (AA, SAS, SSS) and proportional sides — Problem 5 · Task Set 2

Triangle Similarity (AA, SAS, SSS) and Proportional Sides

Grade 10·22 problems·~30 min·ACT Math·topic·act-geo-tri-similar

Work through problems with immediate feedback

Fluency Practice

In $\triangle ABC$ , $AB = 12$ , $AC = 18$ , and $\angle A = 55\degree$ . In $\triangle DEF$ , $DE = 8$ , $DF = 12$ , and $\angle D = 55\degree$ . Are the triangles similar?

Yes, by SAS — two pairs of sides are proportional and the included angles are equal

Yes, by AA — the included angles are equal

No — the side ratios are not equal

No — SAS only works for congruence, not similarity