The Life Starter
Sign up
Grade 4 · unit review

Review: Classify Lines and Figures with Symmetry

Use parallel/perpendicular lines, angle categories, shape attributes, and reflection symmetry.

Download reviews and answer keys

Bring the unit skills together

Use these 4 new cases to check your reasoning. Choices are temporary and are not saved to an account, sent to staff or recorded as school grades. Download your current review choices before leaving or reloading.

Unit review questions
1. Two horizontal lines at different heights in one plane are extended forever. What relationship holds?
Need a hint?
  • Use stated line relationships rather than only a short sketch.
  • Intersecting lines are perpendicular only when the intersection is a right angle.
2. A triangle has angles 25°, 35°, 120°. Classify it by angle.
Need a hint?
  • Angle classification uses degree measures.
  • One acute angle is not enough to prove the whole triangle is acute.
3. Must a square also be a rhombus?
Need a hint?
  • Choose only a category justified by all its required attributes.
  • Do not treat overlapping shape families as mutually exclusive.
4. Does a diagonal of an ideal square give matching reflected halves?
Need a hint?
  • Test matching corner locations after reflection.
  • Equal half-area does not by itself prove symmetry.

The download contains your current choices and any checked feedback. Keep the separate transfer-task work in your own document; downloading its instructions does not mark it complete.

Use the skills in a new task

Describe a square using side directions and symmetry. Explain why an arbitrary diagonal is not a symmetry line for every rectangle.

Work on paper or in your own document. Explain the choices you made.

  • Draw or label the numbers or shape features the task gives you.
  • Say why each calculation or shape choice follows the ideas in this unit.
  • Check that your answer fits the story or drawing in the task.
Compare with a model response

A square has opposite parallel sides and adjacent perpendicular sides. Its two middle lines and two diagonals are symmetry lines. A nonsquare rectangle’s diagonal generally does not reflect the shape onto itself.

A different response can also meet the criteria. Compare the evidence and reasoning, rather than copying the wording.