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.

16. Is ABC similar to AEF? If so, what Is the missing side? y 15 16 x 12 12 A B C E F

17. It often helps to separate the two attached triangles. y 15 16 x 12 12

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

23. Solve by using proportions 4 ft 6 ft 5 ft x

24. Assign: 453: 9; 14, 16, 21a, 23, 26 457: 5-7