Khan Academy Wiki
Surface area using nets
Surface-area 256
Description
Exercise Name: Surface area using nets
Math Missions: 6th grade (U.S.) Math Mission, 7th grade (U.S.) Math Mission8th grade (U.S.) Math Mission, Geometry Math Mission, Mathematics I Math Mission
Types of Problems: 2

The Surface area using nets exercise appears under the 6th grade (U.S.) Math Mission, 7th grade (U.S.) Math Mission8th grade (U.S.) Math Mission, Geometry Math Mission and Mathematics I Math Mission. This exercise practices calculation of surface area and specifically uses nets of 3D shapes to accomplish this.

Types of Problems[]

There are two types of problems in this exercise:

  1. Calculate the surface area: This problem provides a labeled net of a three dimensional solid. The student is asked to calculate the total surface area of the solid.
    Saun1

    Calculate the surface area

  2. Determine if surface area is correct: This problem provides a net of a solid and a claim about the surface area. The student is asked to determine if the claim is true or false and answer accordingly.
    Saun2

    Determine if surface area is correct

Strategies[]

Surface area via nets only requires knowledge of the area formulas for two dimensional shapes. The common ones required for success on this exercise are rectangles and triangles.

  1. Most of the nets are composed of several congruent shapes. Therefore calculating one of the shapes and multiplying by the number of times it occurs can shorten timing.
  2. On the Determine if surface area is correct problem research indicates that when the answer is not correct, it is the sum of some of the sides but not all. This can help to determine "yes" or "no" more quickly.

Real-life Applications[]

  1. Area and perimeter are used in many jobs for architecture and interior design.
  2. The ancient Egyptians from over 4000 years ago were very good at shapes and geometry. Every time the Nile burst its banks and flooded the planes, they had to use geometry to measure their gardens and fields all over again.