An architect is designing a new windmill with four sails. In his ​sketch, the​ sails' center of rotation is the​ origin, (0,0), and the tip of one of the​ sails, point Upper P​, has coordinates left parenthesis negative 6 comma 4 right parenthesis. He wants to make another sketch that shows the windmill after the sails have rotated 90degrees about their center of rotation. What would be the coordinates of Upper P prime​?