What is unterminated character constant error?

here is the code that gives me that error:

Code:#include<stdio.h> #include<conio.h> #include<math.h> main() { float a,b,c,x; printf("Use this to work out the length of the hypotenuse on a right angled triangle.\n"); printf("Please enter a:"); scanf("%f",&a); printf("\nPlease enter b:); scanf("%f",&b); // a*a+b*b=c*c; x=a*a+b*b; c=sqrt(x); printf("\nThe triangle's hypotenuse has a length of %f ",c); getch(); return 0; }

and the part compiler tells me where the error occurs:

Code:printf("\nThe triangle's hypotenuse has a length of %f ",c);