1. 90 Vertical Horizontal Oblique line a b Angles a + b = 180 o Angles at a Point b = 115 o Angle a = 180 – 115 = 65 o

2. Angles at a Point 90 Vertical Horizontal 360 o 1 2 3 4

3. Angles at a Point a b c d Angles at a point add to 360 o Angle a + b + c + d = 360 0

4. 75 o 85 o 80 o a Example 1: Find angle a. Angles at a Point 90 360 o Angle a = 360 - (85 + 75 + 80) = 360 - 240 = 120 o 85 75 80 + 240

5. Angle x = 360 - (90 + 100 + 105) = 360 - 295 = 65 o 90 100 105 + 295 105 o 100 o x Example 2: Find angle x. Angles at a Point 90 360 o

6. 360 o in a circle. What does it mean? 1 2 3 4 90 o 180 o 270 o 360 o