1. Geometric Solids

2. How Can You Describe a Three- Dimensional Figure? Solid figures are also called three-dimensional figures. You can describe many three- dimensional figures by counting the number of faces, edges, and vertices they have.

3. Faces, Edges, and Vertices A face of a solid figure is a flat surface in the shape of a polygon. An edge of a solid figure is a line segment where two faces meet. A vertex of a solid figure is the point where three or more edges meet. The term vertices refers to more than one vertex.

4. These are some 3-D figures you should be able to recognize and describe.

5. Triangular Prism 5 faces (2 triangular, 3 rectangular) 9 edges 6 vertices

6. Rectangular Prism 6 rectangular faces 12 edges 8 vertices

7. Cube 6 square faces 12 edges 8 vertices

8. Triangular Pyramid 4 triangular faces 6 edges 4 vertices

9. Square Pyramid 5 faces (1 square, 4 triangular) 8 edges 5 vertices

10. Curved Surfaces Some three-dimensional figures have a curved surface. Some of these figures also have one or two circular surfaces called bases.

11. Here are some three-dimensional figures with curved surfaces that you should be able to recognize and describe.

12. Cylinder 1 curved surface 2 circular bases

13. Cone 1 curved surface 1 circular base 1 vertex

14. Sphere 1 curved surface

15. Quiz Use your response pad to answer these questions.

16. This shape is called a cone. The arrow is pointing to the cone’s ___. A.vertex B.plane C.base D.edge

17. This block is in the shape of a cube. The arrow is point to the cube’s ______. A.edge B.face C.vertex D.base

18. The refrigerator has the shape of a rectangular prism. The arrow is pointing to the _____ of the rectangular prism. A.base B.vertex C.edge D.face

19. The arrow is pointing to the ____ of the figure. A.edge B.face C.vertex D.base

20. Name the figure. A.pyramid B.cone C.cylinder D.prism

21. Name the figure. A.cylinder B.cube C.cone D.sphere

22. This toy has the shape of a ___. A.cone B.square pyramid C.triangular prism D.cube

23. How many faces? A.12 B.4 C.6 D.8

24. How many edges does this figure have? What is the name of the figure? A.8, rectangular prism B.5, rectangular prism C.8, square pyramid D.5, square pyramid