Warmup Draw the following Line AB Line segment

Warmup Draw the following: Line AB Line segment BC Ray FG

Section 1. 6: Measuring angles LEQ: How do we classify angles?

� An angle is the union of two rays that share a common endpoint.

� There � CED � DEC � E � 3 are 4 ways to name an angle:

� Acute angles have measures between 0 and 90 degrees

� Right angles have measures of exactly 90 degrees (indicated by a small square)

� Obtuse angles have measures between 90 and 180 degrees

� Straight degrees Angle – an angle measuring 180

Right angle Straight angle Acute angle Obtuse angle

� Congruent angles are angles of the same measure(indicated by identical markings)

Postulate 1 -8: Angle Addition Postulate � Similar to the ruler postulate, if point B is in the interior of AOC, then m COB+m BOA=m COA � (<AOC)

� Vertical angles are opposite congruent angles created by the intersection of two lines <1 and <3 are vertical angles <2 and <4 are vertical angles

Why should m<1=m<3

� Adjacent angles are angles that share a common side, common vertex, and no common interior points. � <KIH and <KIJ are adjacent angles

� Complementary angles are two angles who’s measures sum to 90. � � � <TSU and <USV are complementary angles. If m<TSU=42 , what is m<USV? <TSU is the complement of <USV

� Supplementary angles are two angles who’s measures sum to 180. � <TSU and <USV are supplementary angles. � <TSU is the supplement of <USV. � If m<TSU=120 , what is m<USV?

Ex. 1 � Use the adjacent angles below to solve the following: m<HOK = 4 x-6, m <KOB=6 x+2, find x and m<HOK.

How do we measure angles? � Line up the bottom of the protractor with a side of the angle and center of angle with center of protractor. Extend the line of the other side and read the degree.

Hwk: p. 40 -41, 1 -8, 15, 17, 19, 24 -32 odds, 43, 45