Identify Polygons by Sides and Corners
Trace the supplied boundary and count straight sides, checking that it is closed.
About 15 minutes, plus any extended practice
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 closed figure with five straight sides is a pentagon.
- All quantities and shape descriptions are supplied in the worked example and questions; no purchase or personal information is needed.
Learn the idea
A polygon is a closed flat figure built from straight sides. Triangles have three sides, quadrilaterals four, pentagons five, and hexagons six. Turning or stretching a valid example can change its appearance without changing its side count. A curved circle is not a polygon.
Trace the supplied boundary and count straight sides, checking that it is closed. Match the count with a polygon name. Use the same definition regardless of its drawn size or orientation.
Count all sides along one complete trip around the boundary. Equal side lengths are not required for the broad polygon names. Mark each straight side once and count the marks.
- Mark each straight side once and count the marks.
- Follow the worked example. Point to each number or shape feature and say what it tells you.
- Trace the supplied boundary and count straight sides, checking that it is closed.
- Try the question and then the three practice questions. Check your answers and explain any change you make.
See the method in action
A closed figure with five straight sides is a pentagon. It does not need all sides equal to have that name. A circle has no straight polygon sides, so it is not a pentagon or another polygon just because it is closed. Count all sides along one complete trip around the boundary. Equal side lengths are not required for the broad polygon names. Mark each straight side once and count the marks.
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.
Helpful tips
- Count all sides along one complete trip around the boundary.
- Equal side lengths are not required for the broad polygon names.
See the answer and explanation
Triangle
The polygon name is determined by the stated side count, not its size or color.
Take it further
Draw a five-sided polygon with unequal sides. Expected: it is still a pentagon.
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.
More practice: try new cases
Choose an answer for each problem. Explain your method on paper, then use the feedback to decide what to revisit.
Your choices are temporary. Feedback appears after you check all the answers.
Nothing here is saved to an account or sent to a teacher. Keep your own notes or download them before leaving. The score describes these questions; it does not certify subject mastery.
Check the subject sources
These LifeStarter passages, scenarios and exercises are authored for this Academy with AI assistance and review. External resources keep their publishers’ terms. A grade label suggests a starting level; it does not establish alignment with your school’s complete requirements.