2. Similar Triangles

3. Today’s objectives l Understand how the definition of similar polygons applies to triangles. l Recognize similar triangles. l Use the proportional sides of similar triangles to set up algebra problems.

4. Similar triangles are triangles that have three pairs of congruent angles and proportional sides. Similar triangles have the same shape but not necessarily the same size. Definition Triangles ABC and DEF, about to appear, are similar.

5. Similar triangles are triangles that have three pairs of congruent angles and proportional sides. Similar triangles have the same shape but not necessarily the same size. A B C D EF if and only if and the sides are in equal ratios. Definition

6. Example 8 12 6 x Find the value of x. Proportion: Answer: x=9

7. Example x+4 2x-2 Find the value of x. Proportion: Answer: x=8 6 7

8. Example Find the value of x. Proportion: 6 4 5 x Answer: