\(3 \frac{1}{2} r = 28 \\ \frac{7}{2} r = 28 \\ \frac{ \frac{7}{2} }{ \frac{7}{2} } r = \frac{28}{ \frac{7}{2} } \\ r = \frac{ \frac{56}{2} }{ \frac{7}{2} } \\ r= \frac{56}{7}\)
\(1 \frac{1}{2} c =6 \\ \frac{3}{2} c= \frac{12}{2} \\ \frac{ \frac{3}{2} }{ \frac{3}{2} } c= \frac{ \frac{12}{2} }{ \frac{3}{2} } \\ c= \frac{ \frac{12}{2} }{ \frac{3}{2} } = \frac{12}{3} =4 \\ c=4\)
