Welcome Geometry!

1. Welcome Geometry! • Take out your whiteboard and whiteboard pens. • Take out a piece of paper and title it: • 4.1: Classifying Triangles

2. Transformation Test Results Overall, I am very proud of each and everyone of you for putting your best effort into the test. 1st Period • Average 29.6 out of 31 • 95% 3rdPeriod • Average 24.6 out of 31 • 79% 4th Period • Average 26.7 out of 31 • 86% • You will get the tests back sometime this week. I still have students who need to take it! • The scores are on Infinite Campus

3. Do Now!:Whiteboards Classify each angle as acute, obtuse, or right. 1. 2. 3. 4. What are the possible degrees of an acute, obtuse, right, and straight angle.

4. 4.1: Classifying Triangles • Learning Objective • SWBAT classify triangles by their angle measures and side lengths. Tonight's homework: Pg. 219 #1-11 And Classifying Triangles Worksheet

5. 4-1 Classifying Triangles Todays topic is all about classifying triangles, meaning what category do they fall under. We can classify triangles two ways: • By their angle measures. • By their side lengths.

6. C A AB, BC, and AC are the sides of ABC. B 4-1 Classifying Triangles Lets recall how to label the sides and angles. A, B, C are the triangle's vertices.

7. 4-1 Classifying Triangles By Angle Measures Acute Triangle Three acute angles

8. 4-1 Classifying Triangles By Angle Measures Equiangular Triangle Three congruent acute angles

9. 4-1 Classifying Triangles By Angle Measures Right Triangle One right angle

10. 4-1 Classifying Triangles By Angle Measures Obtuse Triangle One obtuse angle

11. 4-1 Classifying Triangles Example 1 Classify all of the triangles in the figure by their angle measures. By Angle Measures

12. Whiteboards Classify ABDby its angle measures.

13. Classifying by Side Lengths By Side Lengths Equilateral Triangle Three congruent sides

14. 4-1 Classifying Triangles By Side Lengths Isosceles Triangle At least two congruent sides

15. 4-1 Classifying Triangles By Side Lengths Scalene Triangle No congruent sides

16. 4-1 Classifying Triangles NOTE: When you look at a figure, you cannot assume segments or angles are congruent based on appearance. They must be marked as congruent using tick or arc marks. By Angle Measures

17. 4-1 Classifying Triangles Example 2 Classify all of the triangles in the figure by their side lengths. By Angle Measures

18. Whiteboards • Classify ACD by its side lengths. • Classify ADB by its side lengths. • Classify ACB by its side lengths.

19. 4-1 Classifying Triangles Example 3 Find the side lengths of JKL. By Angle Measures

20. Whiteboards Find the side lengths of equilateral FGH.

21. Whiteboards Classify each triangle by its angles and sides. 1. MNQ 2.NQP MNP

22. 4-1 Classifying Triangles On the bottom of your notes write down Closure questions: If you do not do them, you will lose participation points. Do the questions all by yourself. I expect to hear no one talking. By Angle Measures

23. Closure Questions • Classify each triangle in the figure by its sides. • Find the side lengths of the triangle.

24. Homework: • Pg. 219 #1-11 And Classifying Triangles Worksheet ( from the front table)