Lesson 50: Reasoning with Shapes
Lesson Objectives
- Define 2-D shapes by their attributes
- Compose 2-D shapes using concrete objects and pictorial representations
- Sort and classify objects
Materials
- Extend Workbook (Page 46)
- 2-D shapes manipulatives
- Highlighters, markers, or crayons
- Whiteboards and dry erase markers
Step 1: Warm Up (5 min)
Review trapezoid and rhombuses in detail, draw them on the whiteboards, have students turn them around and upside down. Have them label the number of sides, edges, and corners. Review previously taught 2-D shapes.
Step 2: Vocab Review (5 min)
Introduce prior vocabulary: open and closed shapes, edges, lines, corners. Explain that all shapes are either open or closed. They are closed if the lines connect or meet. Circles, triangles, rectangles, sequares, pentagons, and hexagons are all closed shapes. These are all described by the number of edges, or lines, and the number of corners, or angles. New vocabulary not previously reviewed: Trapezoid. Explain a Trapezoid has 4 edges and sometimes 2 of the 4 are equal; also, it has 4 corners. Rhombus. Explain a Rhombus has 4 equal edges and have 2 pairs of equal angles. Helpful hint – it looks like a diamond.
Step 3: Model (5 min)
Remind students that shapes can be different sizes and colors – the size and color do not make them for example a circle, the number of edges and corners makes it a circle (or not). Draw out each shape previously taught and ask students how many sides it has and to label each 2-D shape. Have students copy your drawings and labels onto a piece of paper or within a math journal.
Step 4: Guided Practice (5 min)
Ask students to draw a circle, triangle, and square and to label how many edges and corners they have, as well as sides. Students can work in pairs to continue this activity for pentagons and hexagons. Then, draw a shape on the white board, and in pairs, ask students to decide what shape it is, and to list how many edges and corners it has. Continue this activity for each shape: circle, triangle, square, pentagon, hexagon, rhombus, and trapezoid.
Step 5: Student Practice (5 min)
Go to Student Workbook Page (50). Read the directions. Match each shape in the left column to one in the right column. Use the number of edges and corners. Draw a line to connect them. Say the name of the shape.
Step 6: Wrap Up (5 min)
To wrap up the lesson, review the learning objectives and core vocabulary words again and ask your students about their experience.
