The post Measure distance on a map with a scale in C# lets you measure a distance on a map. However, it displays too many significant digits in the results to look nice. For example, the sample picture displays the distance around the lake as 3741.25310780188 feet.
This example uses the ToSignificantDigits extension method describe in the the post Display significant digits in C# to display this value more nicely.
See those two examples and the source code in this post for the details.