set up proportions

1. Similar Triangles Focus – Apply the properties of similar triangles and tomorrow, prove that triangles are similar. Lesson 8-3 WA State Standards: G.3.A and G.3.B

2. Congruent Triangles …have matching angles that are congruent. …have matching sides that are congruent. A B C D F E 100° 35° 45° 115 ft 150 ft 100 ft 150 ft 115 ft 100 ft 35° 100° 45°

3. Congruent Triangles …have matching angles that are congruent. …have matching sides that are congruent. A B C D F E 100° 35° 45° 115 ft 150 ft 100 ft 150 ft 115 ft 100 ft 35° 100° 45°

8. Are they similar? Use Angle/Angle or AA Similarity . Two congruent angles show triangles are similar.

10. Is ABC similar to AEF? A E F C B Sometimes it helps to separate the two triangles and look at each angle separately.

14. Day Two

16. Is ABC similar to AEF?

17. Prove: A line is drawn from a point on one side of a triangle parallel to another side forms a triangle similar to the original triangle.

18. Given: Prove:

20. Assign: 453: 9; 14, 16, 21a 457: 5-7