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 calculate the surface area of a right prism.

3-Dimensional Shapes

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 flat surfaces of three-dimensional figures are called faces. The faces meet at edges. The faces meet at edges. The edges are line segments. The edges are line segments. The edges meet at vertices (plural of vertex). The edges meet at vertices (plural of vertex).

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

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…

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

Triangular prism face base 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. base face

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…

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.

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

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

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

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.

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.

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

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

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

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

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

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

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

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