(a) From the information given, Joseph is planting with a 30-foot rotary cutter.
According to the standard conversion rate,
1 foot equals 0.3048 metres
Therefore, 30 foot would be;
[tex]\begin{gathered} 1ft=0.3048m \\ 30ft=(0.3048\times30)m \\ 30ft=9.144m \\ \text{Therefore the rotary cutter is approx 9 meters wide} \end{gathered}[/tex]