Sines and cosines exists for all multiples of 3 degrees in radicals. Tangent and cotangent may in some case also; but, in some cases, roots of 8th order polynomials are required.
[[The trigonometric table from 3 to 87 by 3 degrees|Section Heading]]
3691215182124273033363942454851545760636669727578818487161(2(3+1)(5−1)−2(3−1)5+5)81(−5+30−65−1)418−22(5+5)41−5−30−65+722−341(5−1)2−−5+30−65+7−421415−6(5+5)+7212−21(5−5)21418−25−6(5+5)+74110−25418−2−5−30−65+781(−5+6(5+5)+1)2141−5+30−65+72121−5−6(5−5)+7+241(5+1)21215−6(5+5)+7+2232121(5−5)+281(5+30−65+1)2121−5+6(5−5)+7+22121(5+5)23+281(5+6(5+5)−1)2121(5+5)+2415+6(5+5)+721215+6(5+5)+7+221215+6(5+5)+7+2415+6(5+5)+72121(5+5)+281(5+6(5+5)−1)23+22121(5+5)2121−5+6(5−5)+7+281(5+30−65+1)2121(5−5)+22321215−6(5+5)+7+241(5+1)2121−5−6(5−5)+7+241−5+30−65+72181(−5+6(5+5)+1)418−2−5−30−65+74110−25418−25−6(5+5)+721212−21(5−5)415−6(5+5)+7418−2−5+30−65+741(5−1)22−341−5−30−65+7418−22(5+5)81(−5+30−65−1)212(5+6(5+5)+7+4)−5−6(5+5)+9Root[$#$18−16$#$17−60$#$16+16$#$15+134$#$14+16$#$13−60$#$12−16$#$1+1&,5,0]−25−215−65+75−25+5+1−105−23(85−385)+232−31−52Root[$#$18+16$#$17−60$#$16−16$#$15+134$#$14−16$#$13−60$#$12+16$#$1+1&,5,0]105−23(385+85)+235−5−25−131Root[$#$18+16$#$17−60$#$16−16$#$15+134$#$14−16$#$13−60$#$12+16$#$1+1&,6,0]5−25Root[$#$18−16$#$17−60$#$16+16$#$15+134$#$14+16$#$13−60$#$12−16$#$1+1&,6,0]25−265+15+71−105+23(85−385)+23Root[$#$18−16$#$17−60$#$16+16$#$15+134$#$14+16$#$13−60$#$12−16$#$1+1&,7,0]1+52Root[$#$18+16$#$17−60$#$16−16$#$15+134$#$14−16$#$13−60$#$12+16$#$1+1&,7,0]35+5−25−1−25+215−65+7Root[$#$18+16$#$17−60$#$16−16$#$15+134$#$14−16$#$13−60$#$12+16$#$1+1&,8,0]25+53+225+265+15+75+25+5+1105+23(385+85)+23Root[$#$18−16$#$17−60$#$16+16$#$15+134$#$14+16$#$13−60$#$12−16$#$1+1&,8,0]2(3+1)(5−1)−2(3−1)5+5165+65+15+28−22(5+5)42(5+65+15+4)23+25+12−−5+30−65+7−425−6(5+5)+742−21(5−5)228−25−6(5+5)+742+528−2−5−30−65+745+15−65−222(5−65+15+4)21−5−6(5−5)+7+225−125−6(5+5)+7+423221(5−5)+22−5+65+15−221−5+6(5−5)+7+222−523+22−5+15−65+221(5+5)+225+6(5+5)+7425+6(5+5)+7+4225+6(5+5)+7+425+6(5+5)+7421(5+5)+22−5+15−65+23+222−5221−5+6(5−5)+7+22−5+65+15−221(5−5)+223225−6(5+5)+7+425−121−5−6(5−5)+7+222(5−65+15+4)25+15−65−28−2−5−30−65+742+528−25−6(5+5)+7422−21(5−5)25−6(5+5)+748−2−5+30−65+745+123+22(5+65+15+4)8−22(5+5)45+65+15+22−5−6(5+5)+92(5+6(5+5)+7+4)Root[$#$18−16$#$17−60$#$16+16$#$15+134$#$14+16$#$13−60$#$12−16$#$1+1&,8,0]105+23(385+85)+235+25+5+125+265+15+73+225+5Root[$#$18+16$#$17−60$#$16−16$#$15+134$#$14−16$#$13−60$#$12+16$#$1+1&,8,0]−25+215−65+75+5−25−13Root[$#$18+16$#$17−60$#$16−16$#$15+134$#$14−16$#$13−60$#$12+16$#$1+1&,7,0]1+52Root[$#$18−16$#$17−60$#$16+16$#$15+134$#$14+16$#$13−60$#$12−16$#$1+1&,7,0]−105+23(85−385)+23125−265+15+7Root[$#$18−16$#$17−60$#$16+16$#$15+134$#$14+16$#$13−60$#$12−16$#$1+1&,6,0]5−25Root[$#$18+16$#$17−60$#$16−16$#$15+134$#$14−16$#$13−60$#$12+16$#$1+1&,6,0]315−5−25−1105−23(385+85)+23Root[$#$18+16$#$17−60$#$16−16$#$15+134$#$14−16$#$13−60$#$12+16$#$1+1&,5,0]1−522−3−105−23(85−385)+235−25+5+1−25−215−65+75+6(5+5)+7+4−5−6(5+5)+9