Download Line and Angle Relationships

Line and Angle Relationships
Step 1: On the back of this sheet is a diagram of 2 intersecting lines.0
Step 2: Find and record the measure of each angle. Remember to place your
protractor down and measure the angle carefully. (the teacher will demonstrate)
Step 3: Color angles that have the same measure.
Analysis of your intersecting lines:
1. For each set of intersecting lines, identify the pairs of angles that have the
same measure.
2. What is true about the sum of the measures of the angles sharing a side?
What do they add up to?
Angles can be classified by their measures.
-Acute angles have measures less than 90° (An acute pain is a sharp pain.)
-Right angles have measures equal to 90° The symbol that we use for right
angles is demonstrated here.)
- Obtuse angles have measures between 90° and 180°.
-Straight angles have measures equal to 180°
Pairs of angles can be classified by their relationship to each other.
Angles with the same measure are called congruent.
Vertical angles are opposite angles formed by intersecting lines. Vertical angles
are congruent. Vertical angles have the same measure.
Adjacent angles have the same vertex, share a common side, and do not
overlap.
The sum of the measures of supplementary angles is 180°.
The sum of the measures of complementary angles is 90°.
Chapter 9 Geometry: Lines and Angle Relationships
-label the acute angles as acute. Why are these angles acute?
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-label the obtuse angles as obtuse. Why are these angles obtuse?
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1. Which angles are congruent? Explain your answer: _____________________
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2. Which angles are vertical angles? Explain your answer: _________________
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3. Which angles are supplementary? Explain your answer. _________________
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Chapter 9 Geometry: Lines and Angle Relationships