Circular Ring
2
2
Area = 0.7854 (D - d ). or 0.7854 (D - d) (D + d)
Example: D = 10", d = 3"
2
2
Area = 0.7854 (10 - 3 ) = 71.4714 sq. in.
Spandrel
2
2
Area = 0.2146 R = 0.1073 C
Example: R = 3 2
Area = 0.2146 X 3 = 1.9314
Parabolic Segment
Ellipse
Irregular Figures
Area may be found as follows:
Divide the figure into equal spaces
as shown by the lines in the figure.
(1) Add lengths of dotted lines.
(2) Divide sum by number of spaces.
(3) Multiply result by A.
Figure 14-37.--Areas and volumes for calculating weights of castings--Continued.
PRINCIPLES OF SURFACE
have a value of 198. This value is now multiplied by
DEVELOPMENT
l/2, resulting in a product of 99. Since all values are in
inches, the area is 99 square inches.
A surface has two dimensions--length and width.
It is bounded by lines that are either straight or curved.
14-22
