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2. 90 Angles at a Point This diagram helps explains why angles at a point add to 360 o. 90 Vertical Horizontal Remember: Angles at a on a line add to 180 o

3. Angles at a Point 90 Vertical Horizontal 360 o 1 2 3 4 This explains why angles at a point add to 360 o.

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

5. 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

6. 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

7. 360 o in a circle. What does it mean? 1 2 3 4 90 o 180 o 270 o 360 o