1. Squares, Rectangles, etc.

Rule. - When The Length Is Given In Feet And The Breadth In Inches, Set The Breadth On B To 12 On A; And Against The Length On A Is The Content In Square Feet On B

If the dimensions are all inches, set the breadth on b to 144 upon A; and against the length upon a is the number of square feet on B.

Required the content of a board 15 inches broad and 14 feet long. Set 15 upon b to 12 upon a; and against 14 upon a is 17.5 square feet on B.

2. Circles, Polygons, etc.

Rule. - Set .7854 upon c to 1 or 10 upon D; then will the lines c and D be a table of areas and diameters.

Areas

3,14

7.06

12.56

19.63

28.27

38.48

50.26

63.61

upon C:

Diam.

2

3

4

5

6

7

8

9

upon D.

In the common rule, set .7854 on c to 10 on d; then c is a line or table of areas, and D of diameters, as before.

Set 7 upon b to 22 upon a; then b and a form or become a table of diameters and circumferences of circles.

Cir.

3.14

6 28

9.42

12.56

15.7

18.85

22

25.13

28.27

upon a.

Dia.

1

2

3

4

5

6

7

8

9

upon b.

Polygons from 3 to 12 sides.-Set the gauge-point upon c to 1 or 10 upon D; and against the length of one side upon v is the area upon C.

Sides

3

5

c

7

8

9

10

11

12

Gauge-points

.433

1.7

2.6

3.63

4.82

6.18

7.69

9.37

11.17

Required the area of an equilateral triangle, each side 12 inches in length.

Set. 433 upon c to 1 upon D; and against 12 upon D are 62.5 square inches upon c.