For the box girder bridge shown, estimate the quantities indicated below.

Note: the fillet in the bottom flange is $0\mathrm{.}35m$ wide $0\mathrm{.}3m$ high, and all dimensions are in metres.

Estimate the combined torsion constant of the two outstand flanges:

$m^4$

Estimate the section$\text{'}$s torsion constant:

$m^4$

answers $=0\mathrm{.}153m4$ and $59\mathrm{.}4m4$