Journal of the Mathematics Council of the Alberta Teachers’ Association
Volume 51 Issue 1, December 2013
7 – 9
A Northern Lights Circle Problem
Gregory V Akulov
When December is incredibly frosty, the famous Dasher and Dancer preface their holiday flight to the Land of Living Skies with a spectacular warm-up. They canter gracefully at a constant rate along the Northern Lights Circle of a radius of 1 km and can be seen by everyone in the Land of the Midnight Sun. Some inhabitants even state that the curious bear Arctic, an awesome navigator from the Coffee Club Island, periodically records the exact straight-line distance between the reindeer. If the map drawn one morning is as shown below, find d. Give an exact answer.
