Table VI.—Corrections for Tangents and Externals. These corrections are to be added to the approximate values, found by dividing the tangent, or external, for a 1° curve (Table IV) by the degree of curve, in order to obtain the true tangents, or externals. Intermediate values may be obtained by interpolation. FOR TANGENTS ADD CENTRAL ANGLE DEGREE OF CURVE 5° 10° 15° 20° 25° 30° 35° 40° 45° 50° 55° 60° 65° 70° 10° .03 .06 .09 .13 .16 .19 .22 .25 .28 .31 .34 .38 .42 .46 15° .04 .10 .14 .19 .24 .29 .34 .39 .45 .51 .53 .58 .63 .68 20° .06 .13 .19 .26 .32 .39 .45 .51 .58 .65 .72 .79 .84 .90 25° .08 .16 .24 .33 .40 .49 .58 .67 .75 .83 .90 .99 1.06 1.14 30° .10 .19 .29 .39 .49 .59 .69 .79 .89 .99 1.09 1.20 1.29 1.39 35° .11 .22 .34 .47 .58 .69 .70 .81 .92 1.04 1.29 1.42 1.54 1.66 40° .13 .26 .40 .53 .67 .80 .93 1.06 1.20 1.34 1.49 1.64 1.79 1.94 45° .15 .30 .44 .60 .76 .91 1.06 1.21 1.37 1.52 1.70 1.87 2.04 2.21 50° .17 .34 .51 .68 .85 1.02 1.19 1.36 1.54 1.72 1.91 2.10 2.29 2.48 55° .19 .38 .57 .76 .95 1.14 1.32 1.52 1.72 1.92 2.14 2.35 2.56 2.77 60° .21 .42 .63 .84 1.05 1.27 1.49 1.71 1.94 2.17 2.38 2.60 2.83 3.07 65° .23 .46 .69 .93 1.16 1.40 1.64 1.88 2.13 2.38 2.63 2.88 3.13 3.39 70° .25 .51 .76 1.02 1.28 1.54 1.80 2.06 2.33 2.60 2.88 3.16 3.44 3.72 75° .27 .56 .83 1.12 1.40 1.69 1.98 2.27 2.57 2.87 3.16 3.47 3.78 4.09 80° .30 .61 .91 1.22 1.53 1.84 2.15 2.46 2.78 3.10 3.44 3.78 4.12 4.46 85° .33 .66 1.00 1.33 1.68 2.02 2.36 2.70 3.05 3.40 3.77 4.14 4.55 4.89 90° .36 .72 1.09 1.45 1.83 2.20 2.57 2.94 3.32 3.70 4.10 4.50 4.91 5.32 95° .39 .79 1.19 1.55 2.00 2.40 2.80 3.20 3.61 4.02 4.40 4.98 5.38 5.83 100° .43 .86 1.30 1.74 2.18 2.62 3.06 3.50 3.95 4.40 4.88 5.37 5.85 6.34 110° .51 1.03 1.56 2.08 2.61 3.14 3.67 4.21 4.76 5.31 5.86 6.43 7.01 7.60 120° .62 1.25 1.93 2.52 3.16 3.81 4.45 5.11 5.77 6.44 7.12 7.80 8.50 9.22 FOR EXTERNALS ADD CENTRAL ANGLE DEGREE OF CURVE 5° 10° 15° 20° 25° 30° 35° 40° 45° 50° 55° 60° 65° 70° 10° .001 .003 .004 .006 .007 .008 .009 .011 .012 .014 .015 .017 .018 .020 15° .003 .007 .010 .014 .018 .023 .027 .029 .032 .035 .039 .043 .047 .051 20° .006 .011 .017 .022 .028 .034 .038 .045 .051 .057 .063 .070 .076 .083 25° .009 .018 .027 .036 .046 .056 .065 .074 .083 .093 .106 .120 .127 .135 30° .013 .025 .038 .051 .065 .078 .090 .103 .116 .129 .149 .170 .179 .188 35° .018 .035 .054 .072 .086 .109 .131 .153 .175 .197 .213 .230 .247 .264 40° .023 .046 .070 .093 .117 .141 .172 .203 .234 .265 .277 .290 .315 .341 45° .030 .060 .093 .119 .153 .184 .216 .254 .289 .325 .351 .378 .411 .445 50° .037 .075 .116 .151 .189 .227 .266 .305 .345 .384 .425 .467 .508 .550 55° .046 .093 .142 .188 .236 .283 .332 .381 .420 .479 .530 .582 .641 .700 60° .056 .112 .168 .225 .283 .340 .398 .457 .516 .575 .636 .697 .774 .851 65° .067 .135 .204 .273 .343 .412 .483 .554 .625 .697 .711 .845 .922 1.01 70° .080 .159 .240 .321 .403 .485 .568 .652 .735 .819 .906 .994 1.08 1.17 75° .095 .182 .286 .383 .480 .578 .678 .777 .877 .977 1.07 1.18 1.29 1.39 80° .110 .220 .332 .445 .558 .671 .787 .903 1.02 1.13 1.25 1.38 1.50 1.62 85° .128 .259 .391 .524 .657 .790 .926 1.06 1.20 1.34 1.47 1.62 1.76 1.91 90° .149 .299 .450 .603 .756 .910 1.07 1.22 1.38 1.54 1.70 1.87 2.03 2.20 95° .174 .350 .522 .706 .985 1.06 1.25 1.43 1.62 1.80 1.99 2.18 2.38 2.53 100° .200 .401 .604 .809 1.01 1.22 1.43 1.64 1.85 2.06 2.28 2.50 2.73 2.96 110° .268 .536 .806 1.08 1.35 1.63 1.91 2.20 2.48 2.76 3.05 3.35 3.66 3.96 120° .360 .721 1.08 1.45 1.82 2.19 2.57 2.95 3.33 3.72 4.11 4.50 4.91 5.32 8