Classifying 2-D Shapes
Unit description: Students will build on their work in third grade classifying triangles, quadrilaterals, pentagons, and hexagons. Students will differentiate between acute, obtuse, and right angles, as well as parallel, perpendicular, and intersecting lines. Students will be able to classify triangles as acute, obtuse, or right, and quadrilaterals as parallelograms, trapezoids, rectangles, rhombi, or squares. Students will also consider symmetry.
Essential Outcomes of the Unit
Geometry- Draw and identify lines and angles, and classify shapes by properties of their lines and angles.
- 4.G.1 Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.
- 4.G.2a. Identify and name triangles based on angle size (right, obtuse, acute).
- 4.G.2b Identify and name all quadrilaterals with 2 pairs of parallel sides as parallelograms.
- 4.G.2c Identify and name all quadrilaterals with four right angles as rectangles.
- 4.G.3 Recognize a line of symmetry for a two-dimensional figure as a line across the figure such that the figure can be folded along the line into matching parts. Identify line-symmetric figures and draw lines of symmetry.
Essential Questions and Big Ideas
How can I describe lines and angles?
- Lines can be described using the terms parallel, perpendicular, and intersecting.
- Angles can be described using the terms acute, obtuse, and right.
How can I classify triangles?
- Triangles can be classified as acute, obtuse, or right.
How can I classify quadrilaterals?
- Quadrilaterals can be classified based on their lines (parallelograms, trapezoids).
- Quadrilaterals can be classified based on their angles (rectangle)
- Quadrilaterals can be classified based on the length of their sides (rhombi, squares)
What is symmetry?
- Symmetric objects can be folded in half and match up.
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