One arc that is longer than a semicirle is arc RPN which is the same as arc NPR. You list 3 points along the arc. The first letter is where the arc starts, the middle letter tells you which direction to go along the circle, and the third letter tells you where the arc stops. We can reverse directions (RPN --> NPR) and describe the same exact arc. The order doesn't matter.
Note: A semicircle arc is one where the endpoints of the arc are along a diameter. For example, arc MPN is a semicircle since points M and N are on the diameter semgnet MN. The arc RPN is compose of arc MPN and minor arc RM.
