MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare these formulas and explain the similarity between them and the formula for the volume of a rectangular solid. Objective: Understand how to calculate the volume of rectangular prisms. Learning target: Answer at least 3 of the 4 volume questions correctly on the exit ticket.
What is a volume? The amount of space inside a 3-dimensional object.
What is a rectangular prism? A 3-dimensional object which has six faces that are all rectangles.
Why is volume measured in units³ (units cubed)? It takes cubes, not squares, to fill up 3-D objects.
How do we find the volume of a rectangular prism? First, find the area of the bottom side. Area of rectangle = length × width Then, multiply the area by the height to fill up the prism. Volume = length × width × height
What is the volume of this rectangular prism? Volume = length × width × height Volume = 3 ft × 6 ft × 2 ft = 18 ft² × 2 ft = 36 ft ³
What is the volume of this rectangular prism? Volume = length × width × height Volume = 4 in × 7 in × 5 in = 28 in² × 5 in = 140 in³
What is the volume of this rectangular prism? Volume = length × width × height Here, the area of the bottom (length × width) is already given to us. Volume = 12 in² × 5 in V = 60 in³
What is the volume of this prism? All prisms have the same volume formula: Find the area of the base (if it’s not given to you) and then multiply it by the height Volume = 18 m² × 6 m V = 108 m³ Remember this for our next lesson!
Draw your own rectangular prism and chose its length, width, and height so that it has a volume of 72 cm³ There are many possible answers! But try to think of a strategy instead of randomly guessing numbers and hoping they will multiply to equal 72.