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Grade 1 · lesson 1 of 4

Separate Defining Attributes from Color

Read the supplied feature choices.

About 15 minutes, plus any extended practice

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Supplied materials

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

Learn the idea

A geometric name depends on features such as straight sides, a closed boundary, and corners. Color, size, and how a drawing is turned are not defining attributes. A triangle can be blue, tiny, or upside down while remaining a closed figure with three straight sides.

Read the supplied feature choices. Select the feature required by the named shape, then draw two different-looking examples that still share it. Explain why a changed color or orientation does not change the definition.

Ask whether changing a feature would change the shape’s definition. Squares are also rectangles; rectangles do not have to have unequal adjacent sides. Make a list of required features separately from optional appearance choices.

  1. Make a list of required features separately from optional appearance choices.
  2. Follow the worked example. Point to each number or shape feature and say what it tells you.
  3. Read the supplied feature choices.
  4. Try the question and then the three practice questions. Check your answers and explain any change you make.
Worked example

See the method in action

For a triangle, three straight sides are defining. Being red is not. A large red triangle and a small blue triangle both have three straight sides forming a closed boundary. An open drawing of three disconnected lines does not make a triangle. Ask whether changing a feature would change the shape’s definition. Squares are also rectangles; rectangles do not have to have unequal adjacent sides. Make a list of required features separately from optional appearance choices.

Your turn

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
  • Ask whether changing a feature would change the shape’s definition.
  • Squares are also rectangles; rectangles do not have to have unequal adjacent sides.
Which feature is required for every triangle?

Feedback appears here after you check. This is practice, not a graded school assessment.

See the answer and explanation

Three straight sides forming a closed figure

Triangles are closed three-sided polygons.

Take it further

Draw two very different triangles. Expected: color, orientation, or size differ while three straight sides remain.

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.

More practice: try new cases
1. Which is required for every rectangle?
Need a hint?
  • Ask whether changing a feature would change the shape’s definition.
  • Squares are also rectangles; rectangles do not have to have unequal adjacent sides.
2. Which feature can change without changing a triangle’s name?
Need a hint?
  • Ask whether changing a feature would change the shape’s definition.
  • Squares are also rectangles; rectangles do not have to have unequal adjacent sides.
3. Which feature can change without changing a square’s name?
Need a hint?
  • Ask whether changing a feature would change the shape’s definition.
  • Squares are also rectangles; rectangles do not have to have unequal adjacent sides.

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.