How do you write a program in C that calculates the area of a triangle given the three x and y coordinates of each corner of the triangle Alongside it must make use of structs.?

Answer 1

To calculate the area of a triangle you need

1. to get the coordinates of the points of the triangles A = (xa, ya), etc (into a structure, eg user input and parsing, direct assignment in the program, etc)
2. calculate area = abs( (xb*ya - xa*yb) + (xc*yb - xb*yc) + (xa*yc - xc*ya) ) / 2
3. put the answer somewhere (eg onto stdout, in the struct for future use, etc).

Your structure would include (at a minimum) the coordinates of the points, eg:

struct triangle

{

int xa, ya;

int xb, yb;

int xc, yc;

};

then you would declare a structure to hold the points and use it to calculate the area, eg:

struct triangle t1;

t1.xa = 0; t1.ya = 0;

t1.xb = 5; t1.yb = 5;

t1,xc = 7; t1.yc = 7;

area = calculate_area(&t1);

To calculate the area, you could put it into a function:

calculate_area(tri)

struct triangle *tru;

{

area;

area = ()abs( (tri->xb * tri->ya - tri->xa * ... )) /* formula above */

return area;

}

I'll let you think about:

1. what the return type ought to be;
2. what type to use to store the triangle's points;
3. any potential error trapping that may need to be done;
4. what compiler options (and header files) you may need.

and put the program together.

Exactly what data you want to store in the struct (minimum the points, but you may want to store the area of the triangle as well - in future you could expand to include calculating the side lengths and angles)