Q$\mathrm{.}2.$ Explain the issues in the measurement of quantities for the following items:

$($a$)$ Provide the unit of measurement and the description for the reinforcement work of R $12mm$ diameter bars of $15\mathrm{.}00m$ long to BS $4449.$

$($b$)$ Provide the unit of measurement and the description for the Class F$4$ formwork to the sides and soffit of a concrete roof beam overall size $450mm400mm300mm$ wide.

$($c$)$ Provide the unit of measurement and descriptions for the excavation work for a water tank where there are some cables in the soil conditions, with excavated depth ranging from $3\mathrm{.}00m$ to $3\mathrm{.}75m$ and blasting not permitted.

$($d$)$ How to measure the formwork to a concrete wall curved to a radius of $12\mathrm{.}00m$ with two structural openings overall size $1000mm1000mm$ and $1050mm1050mm.$