I'm having a hard time understand how to solve these problems. The textbook provides the answers. But I need help understanding the step to get to the answer. ALso some of the images maybe be slightly misfigured. I had a hard time cut and pasting the images.

answers: 
1. a ) 100.0 N. ( b ) 112.5°, 30.0°, 108.7°.
2. 150.0 lb, 1250 lb, 1185.0 lb.
3.  21125 N, 1750 N, 1450 N.

1.  A horizontal circular plate is suspended as shown from three wires that are attached to a support at D and form 30° angles with the vertical. Knowing that the z component of the force exerted by wire BD on the plate is 232.14 N, determine ( a) the tension in wire BD, ( b) the angles ux, uy, and uz that the force exerted at B forms with the coordinate axes.