$\Sigma M_D = 0$
$3A_V + 50(1) = 80(0.75)$
$A_V = 3.33 \, \text{ kN}$
$\Sigma F_H = 0$
$A_H = 80 \, \text{ kN}$
$\Sigma M_A = 0$
$3R_D = 50(2) + 80(0.75)$
$R_D = 53.33 \, \text{ kN}$
At joint A
$\Sigma F_V = 0$
$\frac{3}{5}F_{AB} = 3.33$
$F_{AB} = 5.56 \, \text{ kN tension}$
$\Sigma F_H = 0$
$F_{AE} + \frac{4}{5}F_{AB} = 80$
$F_{AE} + \frac{4}{5}(5.56) = 80$
$F_{AE} = 75.56 \, \text{ kN tension}$
At joint B
$\Sigma F_H = 0$
$F_{BC} = \frac{4}{5}F_{AB}$
$F_{BC} = \frac{4}{5}(5.56)$
$F_{BC} = 4.45 \, \text{ kN tension}$
$\Sigma F_V = 0$
$F_{BE} = \frac{3}{5}F_{AB}$
$F_{BE} = \frac{3}{5}(5.56)$
$F_{BE} = 3.34 \, \text{ kN compression}$
At joint E
$\Sigma F_V = 0$
$\frac{3}{5}F_{CE} = F_{AE}$
$\frac{3}{5}F_{CE} = 3.34$
$F_{CE} = 5.57 \, \text{ kN tension}$
$\Sigma F_H = 0$
$F_{FE} + \frac{4}{5}F_{CE} = F_{AE}$
$F_{FE} + \frac{4}{5}(5.57) = 75.56$
$F_{FE} = 71.11 \, \text{ kN tension}$
At joint F
$\Sigma F_V = 0$
$F_{CF} = 50 \, \text{ kN tension}$
$\Sigma F_H = 0$
$F_{DF} = F_{FE}$
$F_{DF} = 71.11 \, \text{ kN tension}$
At joint C
$\Sigma F_H = 0$
$\frac{4}{5}F_{CD} + \frac{4}{5}F_{CE} + F_{BC} = 80$
$\frac{4}{5}F_{CD} + \frac{4}{5}(5.57) + 4.45 = 80$
$F_{CD} = 88.87 \, \text{ kN compression}$
$\Sigma F_V = 0$
$\frac{3}{5}F_{CD} = \frac{3}{5}F_{CE} + F_{CF}$
$\frac{3}{5}(88.87) = \frac{3}{5}(5.57) + 50$
$53.3 = 53.3$ check
At joint D
$\Sigma F_H = 0$
$\frac{4}{5}F_{CD} = F_{DF}$
$\frac{4}{5}(88.87) = 71.11$
$71.1 = 71.1$ check
$\Sigma F_V = 0$
$R_D = \frac{3}{5}F_{CD}$
$53.33 = \frac{3}{5}(88.87)$
$53.3 = 53.3$ check
Summary
$F_{AB} = 5.56 \, \text{ kN tension}$
$F_{AE} = 75.56 \, \text{ kN tension}$
$F_{BC} = 4.45 \, \text{ kN tension}$
$F_{BE} = 3.34 \, \text{ kN compression}$
$F_{CD} = 88.87 \, \text{ kN compression}$
$F_{CE} = 5.57 \, \text{ kN tension}$
$F_{CF} = 50 \, \text{ kN tension}$
$F_{DF} = 71.11 \, \text{ kN tension}$
$F_{FE} = 71.11 \, \text{ kN tension}$
