Angles Teacher Twins 2014 Warm Up What is

Angles Teacher. Twins© 2014

Warm Up What is an angle? Draw a picture of three different angles.

Angles Flippable

Angle- Two rays with a common endpoint called the vertex. Acute Angleless than 90°. Right Angleexactly 90°. Obtuse anglegreater than 90°. Straight Angleexactly 180°.

Complementary Angles: Two angles whose sum is 90°.

<2 <1 32 + < 2 = 90 90 -32 = 58 < 2 is 58° Example 2: Find the value of x if the angles are complementary. 40◦ + x + 1 = 90 add like terms x + 41 = 90 40° X +1 X = 49° solve the equation

Supplementary Angles: Two angles whose sum is 180°.

Example 1: Angle 3 and angle 4 are supplementary. If < 4 is 126°, how many degrees is < 3? <3 <4 126 + < 3 = 180 -126 = 54 < 3 is 54° Example 2: Angle 1 and angle 2 are supplementary. If < 1 is 52° and < 2 is (2 x + 2)°, what is the value of x? How many degrees is angle 2? 52 + 2 x + 2 = 180 add like terms 54 + 2 x = 180 solve the equation <2 <1 x = 63° < 2 is 2(63) + 2 = 128°

Practice Identify the pairs of angles as complementary or supplementary or neither. Comp. Supp. Neither 1). 45° and 54° 2). 136° and 44° 3). 76°and 104° 4). 26° and 64° Find the value of “x” for each figure. 5). 7). 149 x◦ 25 x◦ 65◦ 31◦ 6). 8). X= 20 (3 x)° 30◦ X=150 25◦ (x + 5)°

Closure Find the measures of <1 , < 2 and < 3. <1 is 90 degrees <2 is 140 degrees <3 is 140 degrees <1 <2 <3 40°