Lesson 5-1 Angle Relationships Obj: I can classify angles and find their measures HWK: p 198 1-24 all

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

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

Use the figure to name the following D C 60 ° 90° 30° 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

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

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

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 26° B C D E