What is Surface Area?

Introducing Surface Area of a Rectangular Prism(Cuboid).

  • Take a few minutes to interact with the rectangular prism shown here. After doing so, create one that has a length = 5 units, width = 4 units, and height = 3 units. ​
  •  Move the CREATE NET to the right to see how Surface Area occurs as a net (envelope). ​
  •  Interact more with the sliders to understand Surface Area. ​
  •  Move the OPTIONS slider through three different steps to see the three sets of faces whose area is added.

Finding Surface Area by examining the NET structure.

  • Check the “Show/Hide net” box.
  • Check the “Show/Hide surface area” box to see the surface area of a unit cube. Note how Surface Area can be found from the net structure.
  •  Move the “length” slider to see the effect on the figure and the surface area.
  • Repeat same with the “width” and “height” sliders.

(A). Draw an example of a right triangle with an area of 6 square units.

(B). Draw an example of an acute triangle with an area of 6 square units.

(C). Draw an example of an obtuse triangle with an area of 6 square units.

Adjust the dimensions of the rectangular prism shown below to create one with the given surface area.

  1. The edge lengths of this prism are positive integers ranging from 1 to 9.​
  2. A prism having LENGTH = 4, WIDTH = 5, and HEIGHT = 6 is equivalent to a prism having LENGTH = 6, WIDTH = 4, and HEIGHT = 5.