B is a right angle.DF is the dotted vertical line from D
With B a right angle its do-able. Consider the little triangle made if you draw a horizontal line across the rhombus on the right from the intersection at angle C to the dotted line. You have have a right triangle and since you know C you know all if its angles, and you know its hypotenuse is 200, so you can solve for all its sides. Then you know the base length of the rhombus and the height. Then you know the base length of the big triangle on the left and its height, and use pythagorean theorem to solve for the hypotenuse.