Lesson 15

• Compare and contrast (orally and in writing) problems that involve surface area and volume of prisms.
• Decide whether to calculate the surface area or volume of a prism to solve a problem in a real-world situation, and justify (orally) the decision.
• Estimate measurements of a prism in a real-world situation, and explain (orally) the estimation strategy.

• Pre-printed slips, cut from copies of the blackline master

Addressing

• 7.G.B.6

• base (of a prism or pyramid)

  The word base can also refer to a face of a polyhedron.

  A prism has two identical bases that are parallel. A pyramid has one base.

  A prism or pyramid is named for the shape of its base.

  

  Expand Image

• cross section

  A cross section is the new face you see when you slice through a three-dimensional figure.

  For example, if you slice a rectangular pyramid parallel to the base, you get a smaller rectangle as the cross section.

• prism

  A prism is a type of polyhedron that has two bases that are identical copies of each other. The bases are connected by rectangles or parallelograms.

  Here are some drawings of prisms.

  

  Expand Image

• pyramid

  A pyramid is a type of polyhedron that has one base. All the other faces are triangles, and they all meet at a single vertex.

  Here are some drawings of pyramids.

  

  Expand Image

• surface area

  The surface area of a polyhedron is the number of square units that covers all the faces of the polyhedron, without any gaps or overlaps.

  For example, if the faces of a cube each have an area of 9 cm², then the surface area of the cube is \(6 \boldcdot 9\), or 54 cm².

• volume

  Volume is the number of cubic units that fill a three-dimensional region, without any gaps or overlaps.

  For example, the volume of this rectangular prism is 60 units³, because it is composed of 3 layers that are each 20 units³.

  

  Expand Image