Name a Shape by Its Edges

Supplied materials

• Paper and a pencil; drawing and spoken explanations are welcome. An adult may read directions and options aloud.
• Supplied worked-case record: A flat closed figure has three straight sides.
• All quantities and shape descriptions are supplied in the worked example and questions; no purchase or personal information is needed.

Learn the idea

A triangle has three straight sides and three corners. A rectangle has four straight sides and four square corners; a square is a special rectangle with four equal sides. A circle has a curved boundary and no corners. Turning a shape does not change its name.

Read the edge and corner description, then match it to a shape. Draw a possible example and trace its boundary. Ignore color and turning when deciding the shape name.

Trace and count the boundary edges. Turning a triangle does not turn it into another shape. Sketch the stated boundary and mark every straight side.

1. Sketch the stated boundary and mark every straight side.
2. Follow the worked example. Point to each number or shape feature and say what it tells you.
3. Read the edge and corner description, then match it to a shape.
4. Try the question and then the three practice questions. Check your answers and explain any change you make.

Check your reasoning

Your answer is temporary and is not saved to an account. Download your current answer before leaving or reloading. Written work on paper or in another app stays in your own file.

Take it further

Draw a large and a small triangle pointing in different directions. Expected: both have three sides.

Nothing here is saved to an account or sent to a teacher. The answer download includes your current choice and any checked feedback. It does not include choices from the separate More practice section. Download that section separately.