What you’ll learn
Use SAS similarity.
Key idea
SAS similarity needs both adjacent side ratios equal, as well as the included-angle match.
SAS needs two proportional corresponding sides and their included angle, not one ratio alone.
Worked example
Enter the exact value or ordered values in the format requested below.
Triangles have equal included angles 90 degrees between corresponding adjacent sides (2,3) and (1,3/2). Find the forward similarity factor.
- The first adjacent ratio equals 1/2.
- For SAS, second adjacent image length is 1/2 times 3=3/2; included angle remains 90 degrees.
Answer: 1/2
Quick Check
Evaluate a worked attempt at use sas similarity, identify the first invalid step, and provide the correction.
Triangles have equal included angles 90 degrees between corresponding adjacent sides (2,4) and (1,4). Student Step 1 computes first ratio 1/2; Step 2 concludes SAS similarity without checking the second. Locate first invalid step and repair.