How did a skyscraper melt a car?

Lesson Plan

Explore the focus and directrix of a parabola, then trace how parallel rays reflect.

1. Question: Ask what students spot and what they are curious about. Read “Twice the window: how bright is its patch?” aloud. Have each student guess and say why.

2. Question: Read “Which rays bounce to the focus?” aloud. Have partners explain their guesses to each other.

3. Big idea: Pause. Ask a student to say the idea in their own words.

4. Real-world application: Ask: Where else have you seen this?

5. Your turn: Have students try their own. Ask them to predict before they test.