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Ηλεκτρ. έκδοση
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Diam. Circum. Area.

90210

90 90 903 90/1

91

91

914

91

92

921

921

92곱

921

92

923

92급

93

93

931

931

93

93

934

934

94

941

94

943

91

94

943

94

95

95

TABLE (Continued).

6,414.86

283.922
284.315 6,432.62

284.707

6,450.40

285.100
285.493

285.886

6,468.21

6,486.04

6,503.90

6,521.78

6,539.68

6,557.61

6,575.56

6,593.54

6,611.55

286.278

286.671

287.064
287.456

287.849

288.242

288.634

6,629.57

289.027

6,647.63

289.420

6,665.70

289.813

6,683.80

290.205

6,701.93

290.598

6,720.08

290.991

6,738.25

291.383

6,756.45

291.776

6,774.68

292.169 6,792.92

292.562

6,811.20

292.954

6,829.49

6,847.82

6,866.16

293.347

293.740

294.132

294.525

294.918

295.310

295.703

296.096

296.488

296.881

297.274

7,032.39

297.667

7,050.98

298.059 7,069.59

298.452 7,088.24
298.845 7,106.90

6,884.53

6,902.93

6,921.35

6,939.79

6,958.26

6,976.76

6,995.28

7,013.82

Diam.

95

95

95

95

95

957

96

961

96

96

96

96

96

96

97

971

97

97

971

97

97

97

98

98

98

98

98

98

983

98급

99

991

99

99

99

99

992

99%

100

Circum. Area.

299.237

299.630

300.023

300.415

300.808

301.201

301.594

301.986

302.379

302.772

303.164

303.557

303.950

304.342

304.735

305.128

305.521

305.913

306.306

306.699

307.091

307.484

307.877

308.270

308.662

309.055

309.448

309.840

310.233

310.626

311.018

311.411

311.804

7,125.59

7,144.31

7,163.04

7,181.81

7,200.60

7,219.41

7,238.25

7,257.11

7,275.99

7,294.91

7,313.84

7,332.80

7,351.79

7,370.79

7,389.83

7,408.89

7,427.97

7,447.08

7,466.21

7,485.37

7,504.55

7,523.75

7,542.98

7,562.24

7,581.52

7,600.82

7,620.15

7,639.50

7,658.88

7,678.28

7,697.71

7,717.16

7,736.63

[blocks in formation]

The preceding table may be used to determine the diameter when the circumference or area is known. Thus, the diameter of a circle having an area of 7,200 sq. in. is, approximately, 95 in.

DECIMAL EQUIVALENTS OF PARTS OF ONE INCH.

.281250

17-32.531250
35-64 .546875

1-64 .015625 17-64 .265625 33-64 .515625 49-64 .765625
1-32 .031250 9-32
3-64 .046875 19-64
1-16 .062500 5-16
5-64 .078125 21-64
3-32 .093750 11-32 .343750
7-64.109375 | 23-64.359375
1-8 .125000 3-8 .375000
9-64.140625 25-64

.296875
.312500
.328125

9-16 .562500
37-64.578125
19-32.593750
39-64.609375

.390625

.406250

5-8 .625000 41-64 .610625 21-32.656250 43-64 .671875 U-IS

.421875

.437500

.687500

5-32 .156250 13-32 11-64 .171875 27-64 3-16 .187500 7-16 13-64.203125 29-64 7-32 .218750 15-32 15-64 .234375 31-64 .484375 47-64 .734375 1-4 .250000 1-2 .500000 3-4

45-64

.703125

.453125
.468750 23-32

.718750

.750000

Inch.

0

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DECIMALS OF A FOOT FOR EACH 1-32 OF AN INCH,

1"

.0469

.0495

.0521

.0547

.0573

.0599

0833

.0026

667 .1693

.0859

.0052

.0885

.1719

.0078 .0911

.1745

.0104 .0937 .1771

.0130 .0964 .1797

.0156

.0990 .1823

.0182

.18-19

.1875

.0234 .1068

.1901

.0260

.1927

.1094
.0286 .1120 .1953

.0312 .1146 .1979

.0339 .1172

.2005

.0365 .1198

.2031

.0391

.1224

.2057

.0117

.1250

.2083

.0443 .1276

.1302

.1328

.1016

.0208 .1012

[blocks in formation]

.1354 .2188

.1380 .2214

.1406

.2210

.1432 .2266

25-32.781250 51-64.796875 13-16 .812500 53-64 .828125 27-32.843750 55-64.859375 7-8 .875000 57-64.890625 29-32.906250 59-64 .921875 15-16 .937500

61-64 .953125 31-32.968750 .984375 1

63-64

1

4"

.2500

.2526

.2552

.2578

.2604

.3437

.2630

.3464

.2656

.3490

.2682

.3516

.2708

.3542

.2734

.3568

.2760

.3594

.2786

.3620

.2812 .3646

.2839

.3672

.2865

.3698

.2891

.3724

.2917

.3750

.2109 .2913

.3776

.2135 .2969

.3802

.2161

.2995

.3828

.3021 .3854

.3047

.3880

.3073

.3099

.3333

.3359

.3385

.3411

.3906

.3932

5′′

.4167

.4193

.4219

.4245

.4271

.4297

.4323

.4349

.4375

4401

.4427

.4453

.4479

.4505

.4531

.4557

.4583

.4609

.4635

.4661

.4688

.4714

.4740

.4766

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0"

.0625

.0651

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TABLE (Continued).

1"

6"

.1458

.1484

.1510

2292

.2318

.0677

.2344

.0703

.1536

.2370

.0729

.1562

.2396

.0755

.1589

.2422

.0781 .1615 .2448
.0807 .1641 .2474

ייך

2"

.5000 .5833
.5026 .5859

.5052 .5885
.5078
.5104 .5937

.5130 .5964

.5156

.5182

.5208

.6042

.5234 .6068

.5260 .6094

.5286 .6120

.5312 .6146

.5339 .6172

.5365

.6198

.5391

.6224

.5417

.5443

.5469 .6302

DECIMALS OF A FOOT FOR EACH 1-32 OF AN INCH.

Inch.

10"

11"

.9167

.9193

.9219

.9245

.9271

.9297

.9323

.9349

.9375

.9401

.9427

.9453

.9479

8"

.6667

.6693

.6719

.5911 .6745

.6771

.6797

.5990 .6823

.6016

.6849

.6875

.6901

.6927

.6953

.6979

.7005

.7031

.7057

.7083

.6458

.6484

.6250

.6276 .7109

.7135

.5495 .6328 .7161

.5521

.6354

.7188

.5547 .6380

.7214

.5573 .6406 .7240

.5599 .6432

.7266

.5625

.7292

.5651

.7318

.5677

.6510

.7344

.5703 .6536 .7370

.5729 .6562 .7396

.5755 .6589

.7422

.5781 .5807

.6615 .7448

.6641 .7474

3"

.3125

.3151

.3177

.3203

.3229

9"

.7500

.7526

.7552

.7578

.7604

.7630

.7656

.7682

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.7708

.7734

.7760

.7786

.7812

.7839

.7865

.7891

.7917

.7943

.7969

.7995

.8021

.8047

.8073

.8099

.8125

.8151

4"

.4036

.4062

.3255

.4089

.4922

.4115

.4948

.3281
.3307 .4141 .4974

177

.8203

.8229

.8255

.8281

.8307

.3958

.3984

.4010

.8333

.8359

.8385

.8411

.8437

.8464

.8490

.8516

.8542

.8568

.8594

.8620

.8646

.8672

.8698

.8724

.8750

.8776

.8802

5"

.8828

.8854

.8880

.8906

.8932

.8958

.8984

.9010

.9036

.4792

.4818

.4844

.4870

.4896

.9062

.9089

.9115

.9141

.9505

.9531

.9557

.9583

.9609

.9635

.9661

.9688

.9714

.9740

.9766

.9792

.9818

.9844

.9870

.9896

.9922

.9948

.9974

GEOMETRICAL DRAWING.

To erect a perpendicular to the line b c at the point a. With a as a center, and any radius, as a b, strike arcs cutting the line at b and c. From band e as centers, and any radius greater than ba, strike arcs intersecting at d. Draw da, which will be perpendicular to b c at a.

To draw a line parallel to ab. At any points a and b, with a radius equal to the required distance between the lines, draw arcs at c and d. The line cd, tangent to the arcs, will be the required parallel.

To bisect the angle bac. With a as a center, strike an arc cutting the sides of the angle in b and c. With b and c as centers, and any radius, strike arcs intersecting, as at d. Draw da, the bisector.

To erect a perpendicular at the end of a line. Take a center anywhere above the line, as at b. Strike an arc passing through a and cutting the given line at c. Draw a line through c and b, cutting the arc at d. Draw the line ad, which will be the required perpendicular.

To divide a line into any number of equal parts. Let it be required to divide the line ab into 5 equal parts. Draw any line a d, and point off 5 equal divisions, as shown. From 5 draw a line to b and draw 4-4, 3-3', etc. parallel to 5b.

To divide a space between two parallel ines or surfaces (for example, the spacing of risers in a stairway). Draw ab

and ce the given distance apart. Then move a scale along them, until as many spaces are included along a d as there are number of divisions required. Mark the points 1, 2, 3, etc., and draw lines through them parallel to ab and ce.

20

40 30 d

10

a

50

70 80 90

C

The magnitude of an angle depends not upon the length of its sides, but upon the number of degrees contained in the arc of a circle drawn with the vertex as a center. The circle is divided into 360 equal parts, called degrees. To divide a quadrant as shown in the figure, first divide it into 3 parts by the arcs at e and d, chords c d and a e being Then subdivide with dividers.

equal to the radius.

An inscribed angle has its vertex (as c or d) in the circumference of a circle. Any angle inscribed in a semicircle is a right angle, as a c b, or ad b.

a

To draw a circle through three points not in a straight line, as

a, b, and c. Bisect ab and also b c. The two bisectors will intersect in a point d, which will be the center of the required circle.

To find the center of a circular arc, as abc, take a point, as b on the curve, and draw ba and bc. Bisect these lines by perpendiculars; the intersec

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To construct a hexagon from a given side. Describe a circle with a radius ab equal to the given side. Draw a diameter as c b. From c and b as centers, and a radius equal to the given side, draw arcs cutting the circle at k, d, f, and e. Connect c, k, ƒ, b, e, and d.

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