I will use OB as the dotted line segment between O and B in your diagram. Since are distances, where those dotted lines meet OB, they form right angles. So, you can use trigonometry for those smaller triangles. and . Then the angle ABC is just .
I have the answers, just don't know how to some it myself
http://i.imgur.com/rv9h7HB.jpg
I will use OB as the dotted line segment between O and B in your diagram. Since are distances, where those dotted lines meet OB, they form right angles. So, you can use trigonometry for those smaller triangles. and . Then the angle ABC is just .