Slicing Solids
5 min
Teacher Prep
Setup
Narrative
The purpose of this Warm-up is to review important characteristics of prisms, pyramids, and polyhedra. Students should be able to interpret the two-dimensional pictures and three-dimensional objects (understanding that the dotted lines indicate hidden lines) and identify all of the parts of the polyhedra.
Launch
Ask students, “What do you see? Describe the object and its parts as precisely as you can.” Give students 2 minutes of quiet work time, followed by a whole-class discussion.
Student Task
Describe each shape as precisely as you can.
Sample Response
The first image is a triangular prism with a base that is a right triangle.
The second image is a rectangular pyramid with a vertex that is not centered over the base.
The third image is a prism with a base that is a pentagon.
Activity Synthesis (Teacher Notes)
Ask students to describe each shape. Record and display their responses for all to see. After each student shares, ask the group if they have anything to add before moving on to the next shape.
If not mentioned by students, explain:
- A prism is a polyhedron with two identical polygon bases, connected by rectangles.
- A pyramid is a polyhedron with one polygon base, and all other faces are triangles meeting at a point.
- A pyramid does not have to have the point centered over the base.
- The base of a prism or pyramid does not have to be oriented at the bottom.
Standards
- 7.G.6·Solve real-world and mathematical problems involving area, volume and surface area of two- and three-dimensional objects composed of triangles, quadrilaterals, polygons, cubes, and right prisms.
- 7.G.B.6·Solve real-world and mathematical problems involving area, volume and surface area of two- and three-dimensional objects composed of triangles, quadrilaterals, polygons, cubes, and right prisms.
10 min
10 min
Knowledge Components
All skills for this lesson
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Slicing Solids
5 min
Teacher Prep
Setup
Narrative
The purpose of this Warm-up is to review important characteristics of prisms, pyramids, and polyhedra. Students should be able to interpret the two-dimensional pictures and three-dimensional objects (understanding that the dotted lines indicate hidden lines) and identify all of the parts of the polyhedra.
Launch
Ask students, “What do you see? Describe the object and its parts as precisely as you can.” Give students 2 minutes of quiet work time, followed by a whole-class discussion.
Student Task
Describe each shape as precisely as you can.
Sample Response
The first image is a triangular prism with a base that is a right triangle.
The second image is a rectangular pyramid with a vertex that is not centered over the base.
The third image is a prism with a base that is a pentagon.
Activity Synthesis (Teacher Notes)
Ask students to describe each shape. Record and display their responses for all to see. After each student shares, ask the group if they have anything to add before moving on to the next shape.
If not mentioned by students, explain:
- A prism is a polyhedron with two identical polygon bases, connected by rectangles.
- A pyramid is a polyhedron with one polygon base, and all other faces are triangles meeting at a point.
- A pyramid does not have to have the point centered over the base.
- The base of a prism or pyramid does not have to be oriented at the bottom.
Standards
- 7.G.6·Solve real-world and mathematical problems involving area, volume and surface area of two- and three-dimensional objects composed of triangles, quadrilaterals, polygons, cubes, and right prisms.
- 7.G.B.6·Solve real-world and mathematical problems involving area, volume and surface area of two- and three-dimensional objects composed of triangles, quadrilaterals, polygons, cubes, and right prisms.