How to get $35\mathrm{.}9?$

GE $213$ Assignment $4$

In the two$-$link structure shown, the links $BC$ and $CD$ are $33\mathrm{.}8$ mm wide and $7\mathrm{.}94$ mm thick $($into the page$).$ The pins at B and D have a diameter of $6\mathrm{.}87$ mm $,$ and are in single shear $($i$.$e$.,$ with a single supporting block at each location$).$ The pin at C also has a diameter of $6\mathrm{.}87$ mm $.$ The $x-y$ coordinate system shown has its origin at pin B$.$ Pins B and D have the same y$-$coordinate. The allowable magnitude of axial stress in link BC is $138$ MPa $,$ and the allowable shearing stress in pin B is $94\mathrm{.}9$ MPa $.$ For each of these $2$ individual stress requirements, determine the vertical load $P$ that would be allowed according to that requirement. Assume that weights are negligible, and that the given values are exact. Assume that the normal stress on any cross section of a link is uniform over that cross section. Force P is applied to the pin at C $,$ at a location in front of link CD$.$ Also, at C $,$ link CD is in front of link BC $.$

$($Final Answers: $35\mathrm{.}9kN,4\mathrm{.}29kN)$