added third file

Problems/Problem_3/problem_3.c

@@ -0,0 +1,29 @@
+#include<stdio.h>
+int main()
+{
+    int a,b,c;
+    printf("Enter three numbers(a,b,c):");
+    scanf("%d %d %d",&a,&b,&c);
+    if((a*a)==(b*b)+(c*c))
+    {
+        printf("%d %d %d",a,b,c);
+    }
+    else
+    { 
+        if((b*b)==(a*a)+(c*c))
+        {
+            printf("%d %d %d",b,a,c);
+        }
+        else
+        {
+            if((c*c)==(a*a)+(b*b))
+            {
+                printf("%d %d %d",c,a,b);
+            }
+            else
+            {
+                printf("NOPE!");
+            }
+        }
+    }
+}