- One acuteanglein eachtriangleis congruentto an acuteanglein the othertriangle.Also,sincethey are
right triangles,both triangleshavea right angle,and theseright anglesare congruent.The trianglesare
congruentby AA.
8.
- and are congruentright angles. : , so and are congruentalternateinterior
angles.The trianglesare similarby AA.
10.
11.
The river is approximately133 feet wide.
- This seemsto be a goodmodel.The banksare roughlystraightenoughto be lines.The banksappear
to be nearlyparallel.If we can acceptthat parallelstraightlines adequatelyrepresentthe river banks,then
the modelis a goodone.
Similarityby SSS and SAS
LearningObjectives
- Use SSS and SAS to determinewhethertrianglesare similar.
- ApplySSS and SAS to solveproblemsaboutsimilartriangles.
Introduction
You havebeenusingthe AA postulateto workwith similartriangles.AA is easyto stateand to apply. In
addition,thereare othersimilaritypostulatesthat shouldremindyou of someof the congruencepostulates.
Theseare the SSS and SASsimilaritypostulates.Thesepostulateswill give us moretoolsfor recognizing