如图，求大神指点下。

上传得图片看不清，上代码。
//圆得实现。
#import "Circle.h"
#import "Point2D.h"

@implementation Circle
- (BOOL)isInteractWithOther:(Circle *)other
{
    Point2D *p1 = [self point];
    Point2D *p2 = [other point];
    double distance = [p1 distanceWithOther:p2];
   
    double radiusSum = [self radius] + [other radius];
    return radiusSum > distance;
}

+ (BOOL)isInteractBewteenCircle1:(Circle *)c1 andCircle2:(Circle *)c2
{

    return [c1 isInteractWithOther:c2];

}
@end



//圆的声明
#import <Foundation/Foundation.h>

@interface Circle : NSObject
@property double radius;
@property Point2D* point;

- (BOOL)isInteractWithOther:(Circle *)other;

+ (BOOL)isInteractBewteenCircle1:(Circle *)c1 andCircle2:(Circle *)c2;



@end


//main函数
#import <Foundation/Foundation.h>
#import "Point2D.h"
#import "Circle.h"
int main()
{
    Circle *c = [[Circle alloc] init];
    c.radius = 4;
   
   
    Point2D *p1 = [[Point2D alloc] init];
   
    [p1 setX:10 andY:13];
    [c setPoint:p1];
    c.point = p1;
   
   
   
    //double d1 = [Point2D distanceBewteenPoint1:p andPoint2:p2];
    Circle *c1 = [[Circle alloc] init];
   
    c1.radius = 2;
    Point2D *p2 = [[Point2D alloc] init];
    [p2 setX:13 andY:17];
    c1.point = p2;
    BOOL b1 = [p1 isInteractWithOther:p2];
   
   
   
   
    //NSLog(@"%d",b1);
return 0;


报错unused variable"b1"
请大神看下错在那了。