1. The problem statement, all variables and given/known data The question sheet is the attached .jpg file 2. Relevant equations No equations as such, however we are doing radian measure at the moment if that helps at all. Angle measurements do not have to be in radians, they can be in degrees. 3. The attempt at a solution So far we [there are two of us trying to work on this one] have decided to use the cosine rule to find the length d, however we cannot get a value for lambda. Also we think that the dotted line in the second diagram bisects the radius that is parallel to h, we just cant prove it. If we can prove this then we can do the rest of the problem ourselves [we hope].