Surface Area From a Net

Surface Area from a Net

A net is a flat pattern that folds into a 3D solid. To find the surface area, add the areas of all the faces shown in the net.

1) Identify each face

Look at the shapes in the net and decide what each one is: rectangles, squares, triangles, or other polygons. If several faces are the same, you can find one area and multiply.

2) Find the area of each part

Use the correct area formula for each face:

• Rectangle: length × width
• Square: side × side
• Triangle: (\tfrac12 \times \text{base} \times \text{height})

Be careful to use the dimensions that belong to each face in the net.

3) Add all face areas

Once every face area is found, add them together. This total is the surface area.

4) Simplify the final answer

Combine like terms or reduce fractions if needed. Leave the answer in square units.

Check your work

A good check is to make sure every face from the net was counted exactly once. If the solid has matching faces, verify that their areas are equal. Also check that your final unit is squared, such as cm² or in².