How to Construct Geometric Shapes With a Compass & Straight Edge

Use a compass to draw a perfect circle.

Whether you are illustrating a problem, creating an illustration, or sketching out a project, knowing how to create basic geometric shapes can allow you to complete your vision. One large part of drawing shapes is knowing the property of the object you are creating. For example, what makes a square a square? The other element required for creating geometric shapes is having the correct tools for the job. Using a straightedge and a compass, you can create basic shapes.

Instructions

Circles

1. Place a pen or pencil inside in hold. Most brands of compass have a knob that you turn to adjust the grip of the hold.

2. Place the point of the compass on the spot you want the center of your circle to be.

3. Adjust the hinge on the compass to increase or decrease the width of the diameter of your circle.

4. Draw a circle by turning the knob at the top of the compass. Make sure to keep pressure on the compass' needle. Try to complete the circle in one fluid motion.

Triangles

1. Lay the straightedge down onto a piece of paper at the angle you would like to draw your first line.

2. Run your pen or pencil along the side of the straightedge, drawing your first line.

3. Draw the second side of your triangle. Start from one of the end-points of your first line, and once again run your pen along the straightedge to draw a straight line.

4. Connect the two end points to close your triangle.

References

• Maths Teacher: Circles and Using a Compass
• Math Is Fun: Triangles