Mathematics · Primary 4

Active learning ideas

Drawing Perpendicular and Parallel Lines

Active learning helps students grasp geometric constructions because hands-on practice with set squares, rulers, and compasses builds muscle memory and spatial reasoning. When students draw lines themselves, they notice errors immediately and correct them, turning abstract concepts into clear, visible results.

• MOE Syllabus Outcomes
• MOE: Geometry and Measurement - S1

• 25–45 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Stations Rotation
• 45 min · Small Groups

Stations Rotation: Construction Stations

Prepare four stations: one for perpendiculars using set squares on given lines, one for parallels with compasses and transversals, one for perpendicular bisectors, and one for angle bisectors. Groups rotate every 10 minutes, draw on mini-whiteboards, and explain their method to the next group. Conclude with a class share-out.

How do you use a set square to draw a line that is perpendicular to a given line?

Facilitation Tip

During Construction Stations, circulate with a checklist to note which students need reminders about holding the set square firmly against the ruler.

What to look for

Provide students with a worksheet containing several lines. Ask them to use their set square and ruler to draw a line perpendicular to each given line, and a line parallel to each given line. Check for accuracy in their constructions.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 02

• Gallery Walk
• 30 min · Pairs

Pairs Challenge: Rectangle Relay

Pairs take turns constructing a rectangle step-by-step: draw base, perpendiculars at ends, parallels for top, then verify angles. Switch roles after each side. Pairs compete to finish first with accurate measurements, then measure classmates' rectangles.

What tools do you need to draw a line that is parallel to another line?

Facilitation Tip

For the Rectangle Relay, position students so they can clearly see each pair’s rectangle before the next team begins their turn.

What to look for

Give each student a card with a drawing of an angle. Ask them to explain in writing the steps they would take to bisect the angle using a compass and straightedge. Collect these to assess understanding of the construction process.

• Understand
• Apply
• Analyze
• Create
• Relationship Skills
• Social Awareness

Activity 03

• Gallery Walk
• 35 min · Whole Class

Whole Class: Parallel Line Art

Project a base line; students use rulers and set squares to draw multiple parallels at varying distances across paper. Add transversals and measure angles to confirm equality. Display as class artwork showing parallel properties.

Can you construct a rectangle using perpendicular and parallel lines with a set square and ruler?

Facilitation Tip

In Parallel Line Art, model how to use the set square to slide it along the ruler for consistent parallel lines before students start their own designs.

What to look for

Pose the question: 'Can you construct a rectangle using only a set square and ruler?' Facilitate a class discussion where students explain their reasoning, referencing the properties of perpendicular and parallel lines they have learned.

• Understand
• Apply
• Analyze
• Create
• Relationship Skills
• Social Awareness

Activity 04

• Gallery Walk
• 25 min · Individual

Individual: Bisector Hunt

Give each student a pre-drawn angle or line segment. They construct bisectors using compasses, label midpoints, and create symmetric designs around them. Collect for a gallery walk with peer checks.

How do you use a set square to draw a line that is perpendicular to a given line?

What to look for

Provide students with a worksheet containing several lines. Ask them to use their set square and ruler to draw a line perpendicular to each given line, and a line parallel to each given line. Check for accuracy in their constructions.

• Understand
• Apply
• Analyze
• Create
• Relationship Skills
• Social Awareness

A few notes on teaching this unit

Teachers should first model each construction slowly, emphasizing the importance of anchor points and tool alignment. Avoid rushing; allow time for students to troubleshoot their own errors before offering help. Research shows that students retain geometric constructions better when they teach the steps to peers, which is why pair and group activities are central to this unit.

Students will demonstrate precise use of tools to create perpendicular and parallel lines, with constructions meeting at exact 90-degree angles or maintaining uniform distance. They will explain their steps with accuracy and justify their methods using geometric properties.

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Watch Out for These Misconceptions

• During Parallel Line Art, watch for students who assume parallel lines must be horizontal or vertical, ignoring slanted orientations.

  Have students rotate their papers to prove that parallel lines maintain equal distance regardless of angle, using their set squares to verify slopes.

• During Rectangle Relay, watch for students who create right angles but do not check that opposite sides are equal or parallel.

  Require students to measure both adjacent sides and opposite sides with a ruler, and mark equal alternate angles as they construct the rectangle.

• During Bisector Hunt, watch for students who draw a line that splits the angle visually but does not use compass arcs to confirm equal angles.

  Have students label the arcs and measure the resulting angles with a protractor to reinforce the compass’s role in verifying equal division.

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Methods used in this brief

• Stations Rotation
• Gallery Walk