<prompt> Ikiwa kipimo cha pembe C ni mara mbili ya kipimo cha pembe B, ni kipimo gani cha pembe A katika pembetatu ABC?asyjozi A,B,C;A0,0;B5,0;C-0.8,2.5;choraA--B--C--A;leboA,A,SW;leboB,B,SE;leboC,C,N;chora4,0.6 ..3.8,0.4..3.9,0.1,ArcArrow;lebo21circ,4,0.6,E;asy  <response>: Kwa kuwa kipimo cha angle C ni mara mbili ya kipimo cha angle B, angle C 2cdot 21circ 42circ. Inafuata kwamba angle A 180circ - 21circ - 42circ 117circ. 