Answer:
The surface area is the sum of the area of all faces of the 3D shape.
For Example.
If the length of a cube is 6cm. To work out the surface area you would first have to find the area. You can do this by multiplying 6 by 6, which gives you 36. You would then multiply 36 by 6, which gives you 216. This is because the cube has 6 faces.
1) Find the area of one face.
2) Multiply by the number of faces.