1. Warm Up Classify each angle as acute, obtuse, or right. 1. 2. 3. 4. If the perimeter is 47, find x and the lengths of the three sides. (Hint: How do you find the perimeter of a triangle?)

2. 3.1 Triangles and Angles Objective: Classify _________ by their ________ and _________. Find angle ___________ in triangles. triangles angles measures

3. A triangle is a figure formed by ________ ___________ joining three _____________ points. A triangle can be classified by its _______________ and by its ________________. Triangle Classification three segments noncollinear angles

4. Points A, B, and C are vertices (singular- vertex) of the triangle, that we can call ΔABC. AB and BC are ___________________sides. AC is the side _______________ B. adjacent opposite

5. Example: Classify the triangle by its sides and angles. What do I know about the sides? Equal or Unequal? What do I know about the angles?

6. Example: Classify the triangle by its sides and angles. What do I know about the sides? Equal or Unequal? What do I know about the angles?

7. Example: Classify the triangle by its sides and angles. What do I know about the sides? Equal or Unequal? What do I know about the angles?

8. Angles

9. Example 4:

10. Use the diagram drawn from the information collected to find the measure of each angle. m  XYZ = m  YXW = m  YWZ = Example 5:

11. The diagram is a map showing John's house, Kay's house, and the grocery store. What is the angle the two houses make with the store? Example 6:

12. Example 7: Find the value of x. What do I know about the angles?

13. Example 8: Find the value of x. What do I know about the angles? 8x

14. Example 9:

15. A B C 3. Triangle Sum Thm. 1. Given 2. Def. of Equiangular Triangle 4. Subst. Prop. 5. Simplify 6. Div. Prop. Example 10: