1. GEOMETRY Section 1.5: Angle Relationships

2. Adjacent angles - two angles that lie in the same plane and have a common vertex and common side, but no common interior points.

3. Linear pair - pair of adjacent angles with noncommon sides that are opposite rays.

4. Vertical Angles - two nonadjacent angles formed by two intersecting lines Vertical angles are ALWAYS congruent.

5. Ex 1: Find the value of the variables. (2x +25)° (3x-10)° (5y)°

6. Complementary angles - two angles with measures that have a sum of 90 degrees. Supplementary angles - two angles with measures that have a sum of 180 degrees The angles in a linear pair are supplementary.

7. Example 2: Find the measures of supplementary angles if the measure of one angle is 6 less than 5 times the measure of the other angle. (5x-6) + (x) = 180 6x – 6 = 180 6x = 186 x = 31 31°, 149°

8. Perpendicular lines intersect to form four right angles. They intersect to form congruent adjacent angles.

9. E XAMPLE 3 Find the value of x so that line m line n (10x-10)°

10. H OMEWORK Page 50: Problems 1-7 all, 8-42 evens, 49 49 1.5 Quiz next time!