Surface Area

Surface area is like the skin of a 3D object. It is how much space covers the outside of a shape. Think about wrapping a present. The amount of wrapping paper you need is close to the surface area. We measure it in square units, just like area.

Finding Surface Area

A cube has 6 equal square sides. To find its surface area, you find the area of one side and multiply by 6. Other shapes have different numbers of sides. A rectangle box has 6 sides too, but they are not all the same. You add up the area of every face to get the total.

Why It Matters

Surface area is useful in many jobs. Painters use it to know how much paint a wall needs. Builders use it when putting tiles on a roof. Scientists use it to study how things heat up or cool down. Even candy makers use it when they coat treats in chocolate. Surface area helps in lots of real life tasks.

Fun Facts

• The surface area of Earth is about 197 million square miles.
• Sponges have a huge surface area because of all their tiny holes.
• A cube has 6 faces, 12 edges, and 8 corners.

Did You Know?

Your lungs have a huge surface area. If you spread them out flat, they would cover about half of a tennis court.