📚 Topic Summary
When two lines intersect, they form angles. Understanding the relationships between these angles can make solving geometry problems much easier! Key relationships to remember include complementary angles (adding up to $90^{\circ}$), supplementary angles (adding up to $180^{\circ}$), vertical angles (equal), and adjacent angles (sharing a vertex and side).
Parallel lines cut by a transversal also create special angle pairs. Corresponding angles are equal, alternate interior angles are equal, and same-side interior angles are supplementary. Mastering these relationships will unlock many geometry problems!
🔤 Part A: Vocabulary
Match the term with its definition:
| Term |
Definition |
| 1. Complementary Angles |
a. Two angles that add up to $180^{\circ}$ |
| 2. Supplementary Angles |
b. Angles that share a vertex and a side |
| 3. Vertical Angles |
c. Two angles that add up to $90^{\circ}$ |
| 4. Adjacent Angles |
d. Angles that are opposite each other when two lines intersect |
| 5. Transversal |
e. A line that intersects two or more other lines |
✍️ Part B: Fill in the Blanks
Complete the following paragraph with the correct terms:
When a ________ intersects two parallel lines, several angle relationships are formed. ________ angles are on the same side of the transversal and in corresponding positions, and they are ________. ________ interior angles are on opposite sides of the transversal and between the parallel lines, and they are also ________.
🤔 Part C: Critical Thinking
Explain how you can use the concept of supplementary angles to find the measure of an angle if you know the measure of its supplement.