Solución

a.   b=5.7b=5.7
b.   senA=47sen A=\frac{4}{7}, cosA=5.77cosA=\frac{5.7}{7}, tanA=45.7tanA=\frac{4}{5.7}, cscA=74cscA=\frac{7}{4}, secA=75.7secA=\frac{7}{5.7}, cotA=5.74cotA=\frac{5.7}{4}