Angle Properties

7.G.5 Angle Properties

Use facts about supplementary, complementary, vertical, and adjacent angles in a multi-step problem to write and

solve simple equations for an unknown angle in a figure.

​Dr. Tom Giles

Supplementary Angles

• These are two angels that add together and equal 180 degrees

• This feature is nearly always associated with a straight line.

• A straight line has an angle measurement of 180 degrees

Example 1. Two intersecting lines form an 80 degree angle. What is the resulting supplementary angle?

• 180 = 80 + X

• 180 - 80 = 80 - 80 + X

• 100 = X

Multiple Choice

What is the measure of angle x?

• 118

• 62

• 26

Complementary Angles

• Two angles that add together and equal 90 degrees

• This feature will always be a right angle

Example 2. A right angle is intersected by a line forming a 40 degree angle. What is the complementary angle formed by the line?

• 90 = 40 + X

• 90 - 40 = 40 - 40 + X

• 50 = X

Multiple Choice

What is the measure of angle x?

• 105

• 75

• 25

• 15

Vertical Angles

• The angles opposite of each other that are form by intersecting lines

• Vertical angles are always congruent (have the same measurement)

Example 3. Two straight lines intersect forming four vertical angles. Angle A is equal to 45 degrees. What is the measure of angle C if it is directly across from angle A?

• Vertical angles are congurent

• Angle A and Angle C are congruent since they are vertical angles

• Angle C is equal to 45 degrees

Multiple Choice

What is the value of Angle Y?

• 65

• 90

• 115

• 180

Multiple Choice

When two angle measurements add together to equal 180 degrees these angles are called?

• Complementary Angles

• Supplementary Angles

• Vertical Angles

Multiple Choice

When two angle measurements add together to equal 90 degrees these angles are called?

• Complementary Angles

• Supplementary Angles

• Vertical Angles

Multiple Choice

When two intersecting lines form angles that are opposite each other, these angles are called?

• Complementary Angles

• Supplementary Angles

• Vertical Angles

Finding Missing Angles of a Triangle

with variables

Properties of Triangles

• The sum of all the angles in a triangle is 180 degrees

• An exterior angle of a triangle is equal to the sum of its two interior opposite angles

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Multiple Choice

Choose a correct equation to find x.

• 4x - 2 + 12x + 1 = 75

• 4x - 2 + 75 = 12x + 1

• 4x - 2 + 75 + 12x + 1 = 180

• 4x - 2 - 75

Multiple Choice

What is the measure of angle b?

• 36^o

• 36

• 36 degrees

Multiple Choice

Which of the following terms best describes Angle d?

• Remote interior angle
• Corresponding angle
• Exterior angle
• Interior angle

Multiple Choice

Solve for x

• 65

• 65 degrees

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