1. Lesson 5-1 Angle Relationships
Obj: I can classify angles and find their measures HWK: p all

2. Vocab
1) angle – formed by two rays, or sides, with a common endpoint called the vertex
2) right angle – an angle whose measure is 90°
3) acute angle – an angle whose measure is greater than 0° but less than 90°
4) obtuse angle – an angle whose measure is greater than 90° and less than 180°
5) straight angle – an angle whose measure is exactly 180°
6) complementary angles – two angles whose measures add to 90°
7) supplementary angles – two angles whose measures add to 180°
8) adjacent angles – have a common vertex and a common side, but no common interior points
9) vertical angles – nonadjacent angles formed by two intersecting lines
10) congruent angles – angles that have the same measure

3. To name angles we use three letters and a symbol
This is angle ABC or < ABC. The vertex is always the middle letter B C

4. Use the figure to name the followingD C
60 ° ° °
A E B
Ex 1) Name two acute angles Ex 2) Name one right angle Ex 3) Name two obtuse angles Ex 4) Name a pair of complementary angles Ex 5) Name two pairs of supplementary angles

5. Use the diagram to find each angle measure
Ex 6) m<2 is 143° find the m<1 Ex 7) Find the measure of <4 2 3 4

6. Use the diagram to name the following
Ex 8) Name two pairs of adjacent angles Ex 9) Name 2 pairs of vertical angles
A C
G B D
F E

7. Ex 10) A traffic engineer designed a section of roadway where three streets intersect. Based on the diagram, what is the measure of <DBE? A
F ° B C D E