<prompt> AB 20 cm, m pembe A 30circ, na m pembe C 45circ. Onyesha idadi ya sentimeta katika urefu wa overlineBC kwa njia rahisi zaidi ya radical. asykuagiza olympiad; ukubwa 200; kuagiza jiometri; kuagiza grafu; defaultpenlinewidth0.8;jozi A asili, B 10sqrt3,10, C 10sqrt3 10,0;kuchoraLebo20, alignNW,A--B; kuchoraB--C; kuchoraA--C;leboA,A,W; leboB,B,N; leboC,C,E;asy  <response>: Inachora urefu overlineBD inagawanya pembetatu ABC kuwa pembetatu 30-60-90 ABD na 45-45-90 pembetatu BCD:asykuagiza olympiad; ukubwa 200; kuagiza jiometri; kuagiza grafu; defaultpenlinewidth0.8;jozi A asili, B 10sqrt3,10, C 10sqrt3 10,0;kuchoraLebo20, alignNW,A--B; kuchoraB--C; kuchoraA--C;leboA,A,W; leboB,B,N; leboC,C,E;jozi D 10sqrt3,0;leboD,D,S;choraB--D;choraalama ya kuliaB,D,A,40;asyKutoka 30-60-90 pembetatu ABD, tuna BD AB2 10. Kutoka 45-45-90 pembetatu BCD, tuna BC BDsqrt2 10sqrt2. 