Help? :( The diagram shows rays of light from a point source, P, that reach a detector, D, along two paths. One path is a straight line, while the other is bent by reflection off a mirror. What is the value of b, correct to one decimal place? Assume that all the points in the diagram lie in the same plane.

Question

anonymous · Answer

5.4

4.2

3.6 

2.8

anonymous · Answer

attachment

adamaero · Answer

Which law are you going to use? 
Law of cosines or Law of sines?

adamaero · Answer

http://www.mathwarehouse.com/trigonometry/law-of-sines/images/law-of-sines-and-cosines/law-of-sines-and-cosines-picture.png

anonymous · Answer

I got the answer for this one but would you care to help with another?

adamaero · Answer

Close this question and post another
I'll help if I can show you how