The Surface Area is number of square units it takes to exactly cover the surface of a cylinder. Specify the Select Entity option. In this example there are 10 grid squares inside the rectangle.
In order to find an area value using the grid method we need to know the size that a grid square represents.
The default for calculation is Standard. Viewed sideways it has a base of 20m and a height of 14m. Perimeter of Cylinder. When calculating area you have to remember to state the area in square units.