error:unterminated character constant

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);`