Finding the Missing Angle with Algebraic Equations

Vertical angles are always

• acute
• total 180 degrees
• congruent (equal measures)
• adjacent angles

What term is used to describe a pair, or group, of angles that equal 180 degrees?

• Supplementary Angles
• Complementary Angles
• Vertical Angles
• Congruent Angles

Complementary Angles have a sum of ___ degrees.

• 90
• 180
• 360
• 45

Find what the value of x.

• 118
• 108
• 28
• 58

Find the value of x

• -5
• 28
• 19
• -3

If x = 19, what do these angles measure?

• 126° and 54°
• 135° and 45°
• 160° and 20°
• 115° and 65°

Tell whether the angles are complementary or supplementary. Then find the value of x.

• Complementary; x=25
• Complementary; x=5
• Supplementary; x=25
• Supplementary; x=5

Tell whether the angles are complementary or supplementary. Then find the value of x.

• Complementary; x=3.4
• Complementary; x=45
• Supplementary; x=20
• Supplementary; x=175

If x = 20, what are the measures of these angles?

• 40° and 140°
• 35° and 145°
• 70° and 110°
• 60° and 120°

What is the value of x?

• 15
• 16
• 18
• 19