/*   Rodney Biggs    COP3223 Summer 2005   */
/*         prg1.c       05.31.05           */
/*   1a) Distance between two points       */
/* 1b) Trigonometric Functions of an angle */


#include <stdio.h>
#include <math.h>
#define PI = 3.14159

int choice;			/* Declares choice as an integer variable */

	/* The following lines ask the user to select from two choices.  */
	/* The program then calls the appropriate function based on the  */
	/* users input.                                                  */

int main(void)
{
	printf("\nPlease choose an option:\n");
	printf("\n1) Calculate the distance between two points in a plane\n");
	printf("2) Calculate the trigonometric function of an angle\n");
	scanf("%d", &choice);

	if (choice == 1)  {
		root();
		}
	else {
		trig();
		}
	return 0;
}

	/* The following function will calculate the distance between two points. */

int root(void)
{
	float x1, y1, x2, y2, distance;    /* Defines variables as type float */
	
	/* The following lines of code request the user to input 2 pairs of         */
	/* numbers.  Those numbers are then printed onto the screen in paranthesis. */
	/* The numbers are then ran through the distance formula to determine the   */
	/* distance between the two coordinate points.  The resulting distance is   */
	/* then printed onto the screen with two decimal places.                    */
	
	
	printf("\n Please enter any two coordinate pairs. (Ex. x y x y)\n");
	scanf("%f%f%f%f", &x1, &y1, &x2, &y2);
	
	printf("\n(%.2f ,%.2f) (%.2f ,%.2f)\n", x1, y1, x2, y2);
	
	distance = sqrt(((x2-x1)*(x2-x1)) + ((y2-y1)*(y2-y1)));
		
	printf("\nDistance = %.2f\n", distance);
	
	return 0;
}


int trig(void)
{

	float angle_deg, angle_rad, angle_sin, angle_cos, angle_tan;			/* Defines variables as type float */
	
	printf("\nPlease enter the angle, in degrees.\n");
	scanf("%f", &angle_deg);
	
	angle_rad = angle_deg * PI / 180.0;
	
	angle_sin = sin(angle_rad);
	angle_cos = cos(angle_rad);
	angle_tan = tan(angle_rad);
	
	printf("sin(%.1f) = %f", angle_deg, angle_sin);
	printf("cos(%.1f) = %f", angle_deg, angle_cos);
	printf("tan(%.1f) = %f", angle_deg, angle_tan);
	
	return 0;
}