長度 餘弦 角度
\(a=\)5 \(\frac{b^2+c^2-a^2}{2bc}=\)0.7143 \(A=\)44.4\(^{\circ}\)
\(b=\)6 \(\frac{c^2+a^2-b^2}{2ca}=\)0.5429 \(B=\)57.1\(^{\circ}\)
\(c=\)7 \(\frac{a^2+b^2-c^2}{2ab}=\)0.2 \(C=\)78.5\(^{\circ}\)