1. Unit 4D:2-3 Dimensional Shapes
LT5: I can identify three-dimensional figures.
LT6: I can calculate the volume of a cube.
LT7: I can calculate the surface area of a cube.
LT8: I can calculate the volume of a right prism.
LT9: I can identify the two-dimensional shape formed by slicing a three-dimensional figure.

2. 3-Dimensional Shapes

3. The flat surfaces of three-dimensional figures are called faces.
Three-dimensional figures are not flat figures. They have length, width, and height. They are also called solid geometric figures.
The flat surfaces of three-dimensional figures are called faces.
The faces meet at edges.
The edges are line segments.
The edges meet at vertices (plural of vertex).

4. face
cube
vertex
edge
A cube, just like a rectangular prism, has 6 faces (all squares), 8 vertices, and 12 edges.

5. A prism is named based on what type of base you start with
A prism is named based on what type of base you start with. For example, if you start with a rectangle on the base (bottom) you will have constructed a rectangular prism. If you start with a triangle on the base (bottom) you will have constructed a triangular prism.
Let’s view some examples…

6. Rectangular prism
face
base
edge
vertex
A rectangular prism has 6 faces, 8 vertices, and
12 edges.

7. Triangular prism base base face face vertex
A triangular prism has five faces. Its base is a triangle. (Notice that even when the triangular prism sits on a rectangle, the base is still a triangle.) Two of its faces are triangles; three of its faces are rectangles. It has six vertices and nine edges.

8. Just like with prisms, pyramids are also named based on what type of base you start with. For example, if you start with a rectangle on the base (bottom) you will have constructed a rectangular pyramid. If you start with a triangle on the base (bottom) you will have constructed a triangular pyramid.
Let’s view some examples…

9. Rectangular pyramid face vertex base
A rectangular pyramid has 5 faces. Its base is a rectangle or a square and the other 4 faces are triangles. It has 8 edges and 5 vertices.

10. vertex
Triangular pyramid
face
base
A triangular pyramid has four faces. All faces,
including its base, are triangles. It has six edges
and four vertices.

11. vertex
Cone
height
radius
base
A cone is an object that has a circular base and one vertex

12. Cylinder
height
base
radius
A cylinder is a solid object with two identical flat ends that are circular. It also has one curved side.

13. Sphere
A sphere is an object shaped like a ball. Every point on the surface of the sphere is the same distance from the center.

14. You will now join with a partner to “create” some 3-D shapes
You will now join with a partner to “create” some 3-D shapes. You will be given a table to fill in based on the creation you make. You will be finding the number of faces, edges, and vertices of different pyramids and prisms. Complete the entire table. We will then discuss your findings as a group.

15. Now it’s your turn to identify the three-dimensional shapes we have discussed. Complete the following worksheet ONLY identifying what each shape is.

16. Volume of a Cube The formula for finding Volume of a Cube is: V = e³ e

17. Practice
Find the volume of a cube with sides 12cm.

18. Practice
What is the volume of a cube with sides 4.5in?

19. Surface Area of a Cube
The formula for finding Surface Area of a Cube is: SA = 6e² e e e

20. Practice
Find the surface area of a cube with sides 6cm.

21. Practice
What is the surface area of a cube with sides 5.5in?

22. Now it’s your turn to calculate the volume and surface area of a cube
Now it’s your turn to calculate the volume and surface area of a cube. Complete the following worksheet on both sides.

23. Volume of a Right Prism
A right prism is a prism that has its bases perpendicular to its lateral surfaces. The lateral surfaces (faces that are NOT the bases) must be rectangles to be a right prism.
The formula for finding Volume of a Right Prism is: V = Bh (B is the area of the base)
Lateral
surface
Lateral
surface

24. Introduction
The following video will show you an introduction on how to calculate the volume of a right prism.
Volume of a Right Prism

25. Practice

26. Practice

27. Now it’s your turn to calculate the volume of a right prism
Now it’s your turn to calculate the volume of a right prism. Complete the following worksheet stopping when you reach lesson 12-4.