1. Objectives: Classify triangles and find the measures of their angles Use the exterior angles of triangles

2.  The sum of the measures of the angles of a triangle is 180 degrees A BC

3. Find the m ∠ 1. 1. 2. 1 36° 1 15° 17°

4. Using Algebra: Find the values of x, y, and z. 65°z°y°x° 21° 39°

5. Find the measure of each numbered angle: 1. 2. 55° 2 1 3 45° 7 8 40° 9

6. Find the value of the variable: x° (2x)°

7.  Equiangular: all ∠’s are ≅  Acute: all ∠’s are less than 90°  Right: One right angle  Obtuse: One angle greater than 90° (but less than 180°

8.  Equilateral: All sides are ≅  Isosceles: At least 2 sides ≅  Scalene: No ≅ sides

9. Exterior ∠ of a Polygon: Formed by a side and an extension of a side Remote Interior ∠: Non-adjacent, interior ∠’s Triangle Exterior Angle Theorem: m∠ACD = m∠A + m∠ B

10. Find the indicated measures: 1. 2. 125° 1 128.5° 13° 2

11. Find the measure of each numbered angle. Justify your answer. 1. 2. 75°213 48° 78° 23 40°