Math lesson plan · 4th grade (Year 5 in England) · 45 minutes
Parallel and perpendicular lines
Geometry
CCSS 4.G.A.1CCSS 4.G.A.2England: Y3 GeometryEngland: Y4 Geometry
Objective and success criteria
Students will: Parallel and perpendicular lines.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Angles: types and measuring
Leads to: Points, lines, line segments and rays; Name quadrilaterals from their properties
Materials: Rulers and protractors, Squared or dotted paper, Shape cut-outs, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Angles: types and measuring). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- What type of angle is 180°? (acute / right / obtuse / straight / reflex) → straightPrompt: Compare with a right angle (90°) and a straight line (180°).
- Two angles together make a straight line. One is 80°. What is the other, in degrees? → 100Prompt: Angles on a straight line add up to 180°.
- A right angle is split into two parts. One part is 23°. What is the other part, in degrees? → 67Prompt: A right angle is 90°.
Hook · 5 min
- Show a photo of a building, a tile pattern or a road sign and ask what shapes and angles students can spot.
- Share the objective: Parallel and perpendicular lines. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: On Fatima's map, two straight roads cross, but not at a right angle. What are such lines called?
- Step 1: They are intersecting (not perpendicular).
- Answer: intersecting (not perpendicular)
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- On Sam's map, two straight roads never meet, however far they go. What are such lines called? (parallel / perpendicular / intersecting (not perpendicular)) → parallelPrompt: Parallel lines are like train tracks.
- How many pairs of parallel sides does a triangle have? → 0Prompt: Look at opposite sides.
You do: independent practice · 10 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- How many pairs of parallel sides does a square have? → 2Prompt: Look at opposite sides.
- On Felix's map, two straight roads never meet, however far they go. What are such lines called? (parallel / perpendicular / intersecting (not perpendicular)) → parallelPrompt: Parallel lines are like train tracks.
Watch out for
- Thinking a square turned on its corner is no longer a square.
- Reading the wrong scale on a protractor.
Support and stretch
Support
- Review first: Angles: types and measuring.
- Use concrete materials: rulers and protractors.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Move on to: Points, lines, line segments and rays; Name quadrilaterals from their properties.
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/math/grade-4.
Free lesson plan from eurekami.com/lesson-plan-builder