from the side already drawn. A ¼-inch lap is added to the long sides of the pattern at each corner.
All necessary dimensions should be placed on the plan and elevation, and all over-all dimensions on the pattern.
14. Related Mathematics on Candy Pan.—Problem 3A.—The candy pan shown in Fig. 26 is to be made of IXX Charcoal Tin. (Read two cross charcoal tin.) This tin is generally carried in stock in two sizes of sheets, 14″×20″ and 20″×28″. Calculate the area in square inches of a sheet 20″×28″.
Problem 3B.—What is the area of Fig. 29? Use over-all dimensions.
Problem 3C.—What is the largest number of blanks (Fig. 29) that could be cut from a sheet of 20″×28″ tin?
Problem 3D.—What are the dimensions of the pieces of tin left after cutting the blanks from the sheet?
Problem 3E.—What is the total area of the pieces of tin left?
Problem 3F.—Divide the total area of tin wasted (Problem 3E) by the total area of the sheet (Problem 3A). The result will be the percentage of the 20″×28″ that is wasted.
Problem 3G.–Divide the total area of tin wasted (Problem 3E) by the number of blanks obtainable (Problem 3C). This will give the amount of tin wasted per blank. Divide this result by the total area of one blank (Problem 3B) to get the percentage of waste per blank or per pan.
Illustrative Examples
Tin blanks 6″×8″ are to be cut from a sheet of 14″×20″ tin plate. The problem is to find the maximum number of blanks obtainable and the percentage of waste.
| Example of Problem 3A. | ||
| width | 14″ | |
| × | ||
| length | 20″ | |
| 280 sq. in., area. | Ans. 280 sq. in., area. | |
| Example of Problem 3B. | ||
| width | 6″ | |
| × | ||
| length | 8″ | |
| 48 sq. in., area. | Ans. 48 sq. in., area. | |
| Example of Problem 3C. | ||
| (See Fig. 30.) | Ans. 4 blanks. | |
