On the section below, draw foundation elements as indicated.

a$.$ Calsson $4^{\text{'}}(1200mm)$ in diameter with a bell $2\mathrm{.}5$ times this

diameter

b$.$ Precast concrete end bearing pile ${16}^{\text{'}\text{'}}(400mm)$ square

c$.$ Concrete bearing wall ${12}^{\text{'}\text{'}}(300mm)$ thick supported by a strip

footing ${36}^{\text{'}\text{'}}$ wide and ${12}^{\text{'}\text{'}}$ deep $(900300mm)$ resting on soil

${48}^{\text{'}\text{'}}(1200mm)$ below grade

d$.$ Cluster of $16$ wood friction piles, each ${30}^{\text{'}}(9m)$ long with an

average diameter of ${12}^{\text{'}\text{'}}(300mm),$ spaced ${36}^{\text{'}\text{'}}(900mm{)}_{\text{a}\text{n}\text{a}\text{m}}$

Drawn in a form that matches the example on the attached image