Geometry: Shapes, Angles & Symmetry

Subject: Math  ·  Grade level: 4th

Classify polygons, measure angles, and find lines of symmetry in art and nature.

In this lesson

• Polygons — closed shapes with straight sides
• Angles — how lines meet
• Symmetry — mirrored shapes

Key terms

Acute angle

Less than 90°.

Right angle

Exactly 90° — a square corner.

Obtuse angle

Between 90° and 180°.

Straight angle

Exactly 180°.

Geometry: Shapes, Angles & Symmetry lesson on BrightPath

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