Make Some Arcs!
Use a string, pencil, and tape to make a simple compass and draw different arcs and circles, exploring radii, centers, and symmetry.
About this tutorial
Use a string, pencil, and tape to make a simple compass and draw different arcs and circles, exploring radii, centers, and symmetry.
What you need
Instructions
- 1
Step 1
Gather your string pencil tape paper ruler and colouring materials.
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Step 2
Lay the paper flat on a table.
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Step 3
Use the pencil to make a small dot where you want the circle center to be.
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Step 4
Tape one end of the string to the pencil about 5 cm from the pencil tip.
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Step 5
Tape the other end of the string to the center dot on the paper.
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Step 6
Pull the pencil outward until the string is taut and the pencil tip touches the paper.
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Step 7
Keeping the string taut draw a full circle by moving the pencil all the way around the taped center.
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Step 8
Peel the tape off the pencil.
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Step 9
Move the string along the pencil to a new distance from the tip and press tape down to secure it.
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Step 10
Draw a larger or smaller circle or draw only part of the rotation to make an arc.
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Step 11
Peel the tape from the paper center.
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Step 12
Stick the string anchor tape to a new spot on the paper to make a different center.
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Step 13
Draw overlapping circles and arcs from the different centers to explore radii symmetry and patterns.
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Step 14
Share a photo of your finished arcs and circles on DIY.org.
Fun facts
How do I make a simple compass to draw arcs and circles for the 'Make Some Arcs!' activity?
To make a simple compass, tie a 15–30 cm piece of string around a pencil and tape the knot flat. Secure the string’s loose end to the paper at the desired center point (or hold it with a thumb). Pull the pencil taut and rotate it around the center to draw arcs or full circles. Change string length to explore different radii and repeat from new centers to observe symmetry.
What materials do I need to make arcs using string, a pencil, and tape?
You’ll need a pencil, a length of string (about 15–50 cm), and tape to attach the string to the paper. Also use paper or cardstock, scissors to cut the string, and a ruler or measuring tape for precise radii. Optional items: a pushpin instead of tape, extra pencils or markers for thicker lines, and colored paper to compare patterns. Work on a flat surface for best results.
What ages is the 'Make Some Arcs!' activity suitable for?
This activity fits ages roughly 5–12. Preschoolers (4–5) can join with close adult help for handling tape and measuring; ages 6–8 can work more independently while learning radii and centers; ages 9–12 can experiment with symmetry, overlapping circles, and basic angle ideas. Always supervise younger children with scissors or pushpins and adapt challenges to each child’s skill level.
What are the learning benefits of making arcs and exploring centers, radii, and symmetry?
Drawing arcs strengthens spatial reasoning, introduces geometry concepts (center, radius, arc), and practices measurement and fine motor skills. It boosts vocabulary—words like radius and symmetry—and encourages problem solving when children change radii or overlap circles to create patterns. The activity also supports creativity and cooperative play as kids design symmetric shapes, mandalas, or explore how changing the center affects the circle.
Watch & Learn
Need help?
What can we use if we don't have string or tape?
Use yarn, thin shoelace, or dental floss instead of the string and secure it to the pencil with masking tape or a rubber band, and if you lack tape for the paper center, anchor the string under a paperclip or a small washer placed on top of the dot.
My circles come out wobbly or the tape keeps slipping off the pencil—what should I do?
Re-tape the string about 5 cm from the pencil tip using stronger tape or wrap the string once around the pencil before taping, make sure the paper is flat and taped at the edges, and keep the string taut as you draw the circle.
How can I adapt this activity for younger or older children?
For younger children, pre-mark the center dot, use a thick marker and adult help to hold the anchor, while older kids can use the ruler to set exact radii, shift the string to precise distances, and record measurements to study symmetry.
How can we extend or personalize our arcs and circles once we've drawn them?
Try changing the taped distance on the pencil to create layered radii, move the paper center to make overlapping patterns, color different arcs with your colouring materials, or paint inside selected arcs and share a photo on DIY.org as suggested.