7  *

     7  *

     8  */

     8  */

     9 

     9 

    10 #import <CoreGraphics/CoreGraphics.h>

    10 #import <CoreGraphics/CoreGraphics.h>

    11 

    11 

    12 CGFloat distanceBetweenPoints (CGPoint first, CGPoint second);

    15 CGFloat distanceBetweenPoints (CGPoint first, CGPoint second);

    13 CGFloat angleBetweenPoints(CGPoint first, CGPoint second);

    16 CGFloat angleBetweenPoints(CGPoint first, CGPoint second);

    14 CGFloat angleBetweenLines(CGPoint line1Start, CGPoint line1End, CGPoint line2Start, CGPoint lin2End);

    17 CGFloat angleBetweenLines(CGPoint line1Start, CGPoint line1End, CGPoint line2Start, CGPoint lin2End);