Alternate interior angles examples with parallel lines (Grade 7 explained)

📚 Quick Study Guide

• 📏 Parallel Lines: Lines that never intersect.
• transversal cuts across two or more lines.
• 📐 Alternate Interior Angles: Angles that lie on opposite sides of the transversal and are inside the parallel lines.
• 🤝 Key Property: When parallel lines are cut by a transversal, alternate interior angles are congruent (equal).
• ✍️ Example: If one alternate interior angle measures 60°, the other also measures 60°.

Practice Quiz

1. What are alternate interior angles?
1. Angles on the same side of the transversal.
2. Angles inside the parallel lines and on opposite sides of the transversal.
3. Angles outside the parallel lines.
4. Angles that add up to 90 degrees.
2. If two parallel lines are cut by a transversal and one alternate interior angle measures 45°, what is the measure of the other alternate interior angle?
1. 135°
2. 45°
3. 90°
4. Cannot be determined
3. Which of the following is NOT a property of alternate interior angles formed by parallel lines and a transversal?
1. They are congruent.
2. They lie on opposite sides of the transversal.
3. They are supplementary.
4. They are inside the parallel lines.
4. In the diagram below, lines $l$ and $m$ are parallel. If angle 1 measures 110°, what is the measure of its alternate interior angle?
1. 70°
2. 110°
3. 90°
4. 20°
5. What happens to the alternate interior angles if the lines are NOT parallel?
1. They remain congruent.
2. They are still alternate interior angles but are not necessarily congruent.
3. They disappear.
4. They become right angles.
6. If one alternate interior angle is represented by $2x$ and the other by 50°, what is the value of $x$?
1. 100
2. 25
3. 50
4. 20
7. Which of the following provides the best real-world example of alternate interior angles?
1. The hands of a clock.
2. A pair of intersecting streets.
3. A railroad track crossing a straight road.
4. The adjacent sides of a square.