Similarity Criteria Math Example 3
Follow the full solution, then compare it with the other examples linked below.
Example 3
mediumTriangle ABC has sides , , . Triangle DEF has sides , , . Prove the triangles are similar and state the criterion used.
Solution
- 1 Step 1: Order the sides of each triangle from smallest to largest. : . : .
- 2 Step 2: Compute the ratios of corresponding sides: , , .
- 3 Step 3: All three ratios are equal (), so every pair of corresponding sides is proportional.
- 4 Step 4: By SSS~ (Side-Side-Side Similarity), with scale factor .
Answer
by SSS~ with scale factor .
SSS~ states that if all three pairs of corresponding sides of two triangles are in the same ratio, the triangles are similar. Note that both triangles here are also right triangles ( and ), so AA~ would also apply since both contain a angle.
About Similarity Criteria
Three sets of conditions that guarantee two triangles are similar: AA (two pairs of equal angles), SAS~ (two pairs of proportional sides with equal included angle), and SSS~ (all three pairs of sides in the same ratio).
Learn more about Similarity Criteria →More Similarity Criteria Examples
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