Drill If you have a octagon where the sum of 7 of the angles is 960 degrees what is the measure of the eighth angle? What type of polygon would you get if you took the number of sides in a dodecagon and subtract the number of sides in a heptagon?

Chapter 2 Geometric Figures

2.3 Parallel and Perpendicular Lines in a Coordinate Plane

Vocabulary Slope: Rate of change, Rise over Run Change in “y” over the change in “x”

Theorems If two lines are parallel to a third line then they must be parallel to each other. In a plane, two lines perpendicular to a third line must be parallel to each other. The slopes of two lines must be the same if they are parallel. The slopes of two perpendicular lines are negative reciprocals of each other.

Examples 1) y = 3x + 4 2) y = ½ x + 4 y = 3x – 8 y = -2x + 3

Homework Page 86 #’s 1, 2, 6, 8, 13, 16, 17