Problem 418 - Warren Truss by Method of Sections

$\frac{2}{\sqrt{5}}F_{BC} = 40$

$F_{BC} = 44.721 ~ \text{kN}$   compression       answer

$6F_{CE} + 9(40) = 3(140)$

$F_{CE} = 10 ~ \text{kN}$   tension       answer

$6F_{DF} + 3(80) + 12(40) = 6(140) + 6(60)$

$F_{DF} = 80 ~ \text{kN}$   compression       answer