| 
 
				
					
					| 
      Geometric Art: Isolines or Contour Lines of Problem 1150, Circle, Perpendicular Secants, 90 Degrees, 
	  Parallel Lines |  
				| 
	      			 |  
				| 
							
							Isoline
 An isoline or contour line of a function of two variables
										 is a curve along which the function has a constant value. Isolines usually have a parallel trend.
 
 See
				also:
 Original problem 1150
 
 |  |