added new task

SelfEducation/Task/T4/dist/func.c

@@ -0,0 +1,29 @@
+#include <stdio.h>
+#include <math.h>
+#include <stdlib.h>
+
+float dist(int x1, int y1, int x2, int y2)
+{
+    float res, a, b;
+
+    a = abs(x1 - x2);
+    b = abs(y1 - y2);
+    res = sqrt(a * a + b * b);
+
+    return res;
+}
+
+float area_geron(int x1, int y1, int x2, int y2, int x3, int y3)
+{
+    float res, p, a, b, c;
+
+    a = dist(x1, y1, x2, y2);
+    b = dist(x2, y2, x3, y3);
+    c = dist(x1, y1, x3, y3);
+
+    p = (a + b + c) / 2;
+
+    res = sqrt(p * (p - a) * (p - b) * (p - c));
+
+    return res;
+}