Angles TeacherTwins©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 Angle- less than 90°. Right Angle- exactly 90°. Obtuse angle- greater than 90°. Straight Angle- exactly 180°.

Complementary Angles: Two angles whose sum is 90°.

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

Supplementary Angles: Two angles whose sum is 180°.

Example 1: Angle 3 and angle 4 are supplementary Example 1: Angle 3 and angle 4 are supplementary. If < 4 is 126°, how many degrees is < 3? 126 + < 3 = 180 180 -126 = 54 < 3 is 54° < 3 < 4 Example 2: Angle 1 and angle 2 are supplementary. If < 1 is 52° and < 2 is (2x + 2)°, what is the value of x? How many degrees is angle 2? 52 + 2x + 2 = 180 add like terms 54 + 2x = 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. 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). 6). 7). 8). Supp. Comp. Neither Supp. 149 X= 20 30◦ x◦ 31◦ (3x)° 25 X=150 x◦ 65◦ (x + 5)° 25◦

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