Proving Triangles are similar
Are these two triangles similar? How do you know? How can you prove they are similar?
How are Proportions used with Similar Figures?
Proportions are to find missing side lengths in similar figures because similar figures must have sides lengths that are proportionate (the same ratio). 1. Identify the corresponding sides 2. Set up a proportion. One of the ratios must be the missing side and its' corresponding side. The second ratio is two corresponding sides with known lengths. 3. Solve the proportion for the unknown value. 4. Check to make sure side lengths have the same ratio. |
Proving Triangles are Similar using Postulates and Theorems
In chapter 4 we proved triangles were congruent by using congruence postulates and theorems (SSS, SAS, HL, ASA & AAS) and we wrote congruence statements to show corresponding parts. In chapter 6 we will be writing and using similarity statements and using proportions, ratios and postulates and theorems to prove two triangles are similar; including AA, SSS and SAS. You must understand what it means to be congruent and what it means to be similar. While the two concepts have similarities they also have major differences.