Section 4.2 Surface Area In this section the Surface Area we will address will relate to the measure of surfaces of 3 dimensional objects. One way to look at it is in terms of in some determining how much “area” you would be “painting” or “coating” way if you covered all (or sometimes part) of the surfaces of a three dimension object. Example: In the box show on the right we need to consider the following: What are we What shapes do you see? “covering?” Inside Trapezoids Outside Triangle Bottom Rectangles Top Rounded edges How accurate I need to be depends on the Is the bottom flush or not? What is the thickness of the application. material? In order to find the requested surface area, you will more than likely have to divide the objects in shapes that you know. a cheap paint, it If I’m using won’t matter. gold leaf, every square inch matters. If I’m using Homework: Problems 1-8. Before leaving class today, it is important that we review every homework problem to lay out a possible approach for solving. Example 1 Find the surface area of the plate. • 38 cm diameter 4 cm thick • 6 cm diameter holes drilled through •
Section 4.2 Surface Area In this section the Surface Area we will address will relate to the measure of surfaces of 3 dimensional objects. One way to look at it is in terms of determining how much “area” you would be “painting” or “coating” in some way if you covered all (or sometimes part) of the surfaces of a three dimension object. Example: In the box show on the right we need to consider the following: What are we “covering?” Inside Outside Bottom Top What shapes do you see? Trapezoids Triangle Rectangles Rounded edges Is the bottom flush or not? What is the thickness of the material? In order to find the requested surface area, you will more than likely have to divide the objects in shapes that you know. How accurate I need to be depends on the application. If I’m using a cheap paint, it won’t matter. If I’m using gold leaf, every square inch matters. Homework: Problems 1-8. Before leaving class today, it is important that we review every homework problem to lay out a possible approach for solving. Example 1 Find the surface area of the plate. • 38 cm diameter • 4 cm thick • 6 cm diameter holes drilled through