Surface Area of Prisms, Cylinders and Complex Solids

Lateral surface area is the combined area of the surfaces on the sides of a solid and does not include the area(s) of the base(s)

We can find the lateral surface area of prisms by multiplying the perimeter of the base by the height

The surface area of a solid is the sum of the areas of all its surfaces, or faces

A two dimensional pattern of a solid, called a net, can be sketched to visualize all the surfaces of the prism

The areas of individual surfaces can then be added to get the total surface area

The net of a cylinder is a rectangle and 2 circles

Surface Area of a cylinder = Area of its 2 bases + Area of the curved surface (rectangle)

Surface Area of a cylinder = 2∏r² + 2∏rh

The lateral or curved surface area of a cylinder is calculated by multiplying the circumference of the base by the height

The curved surface area of a cylinder is 2∏rh

To find the effect of change in dimensions on the surface area, find the ratio of the new and the original surface areas

The same change in the radius and the height of the cylinder would have different effects on the change in surface areas. Change in radius would affect the surface area more than the change in height

Surface area of composite figures can be found by dividing them into simpler figures

Surface area of a composite figure = Sum of the areas of the contributing figures

If any face of the complex figures is not exposed to the outside, then its area would not be counted even once