I don't understand how to even start.. would someone help me solve it?

You are driving along a lonely stretch of highway and are coming upon a dip in the road. The dip is composed of 4 identical circular arcs of 3 degrees. Each arc has a radius of 1028 feet and the arcs are tangent to each other. If there is some sort of obstruction (on coming truck,deer.. ) in the middle of the dip how tall does it need to be to reach your line of sight? Assume your line of sight is 41 inches above the road.