Use method of section and draw FBD in each section. Take clockwise as positive and counterclockwise as negative.
Extracted text: F6-9. Determine the force in members KJ, KD, and CD of the Pratt truss. State if the members are in tension or compression. K 3 m B |F |-2 m-|-2 m-|-2 m--2 m-|-2 m-|-2 m-| 20 kN 30 kN 40 kN
Extracted text: F6-8. Determine the force in members LK, KC, and CD of the Pratt truss. State if the members are in tension or compression. 3 m B. [C |F -2 m--2 m--2 m--2 m-|-2 m-|-2 m-| 20 kN 30 kN 40 kN