The pie$-$chart shows the proportion of the staff in Compan A who work in sales $/$ office $/$ support $/$ workshop when thi workfoce totalled $260$ employees on $1$st June $2017.($i$)$ Using a protractor, find the size of the angles in $($a$)$ workshop $($b$)$ office $($c$)$ support. $($ii$)$ Find the number of people who worked in $($a$)$ workshop $($b$)$ office $($c$)$ support $($d$)$ sales. On $1$st June $2016,$ the number of support staff was exactly half the number of sales staff. The support staff then was of the workforce. The sales staff increased by from $1$st June, $2016$ to $1$st June $2017.$ Calculate the size of the worforce on the $1$st June $2016.$