commit e54914f130dcfe04fa8531ac3ca096d5c8974bed
parent e9b035593fdff0c5660a82c04fae8b4f46718e22
Author: Amit Dutta <amitdutta4255@gmail.com>
Date: Fri, 3 Oct 2025 19:53:18 +0530
ADD_LUC019
Diffstat:
1 file changed, 53 insertions(+), 0 deletions(-)
diff --git a/Letusc-exercises/luc019.c b/Letusc-exercises/luc019.c
@@ -0,0 +1,52 @@
+/* If the length of three sides of a triangle are entered through the
+keyboard, write a program to check whether the triangle is an isosceles,
+an equilateral, a scalene or a right-angled triangle. */
+/* Author - Amit Dutta, Date - 3rd OCT, 2025 */
+/* Let Us C, Chap- 4, Page - 71, Qn No.: D(a) */
+
+#include <stdio.h>
+#include <math.h>
+
+#define EPSILON 0.000001
+/* EPSILON is used to compare double values for approximate equality,
+mitigating floating-point precision errors. */
+
+int main()
+{
+ double side1, side2, side3;
+ printf("Please enter the length of three side of the triangle : ");
+ scanf("%lf %lf %lf", &side1, &side2, &side3);
+ if (side1 < 1 || side2 < 1 || side3 < 1)
+ {
+ printf("\nLength of a side of triangle should be a positive integer.");
+ return 1;
+ }
+ if (side1 + side2 < side3 || side1 + side3 < side2 || side2 + side3 < side1)
+ {
+ printf("\nEntered triangle is not VALID.");
+ return 1;
+ }
+ // isosceles check
+ if (side1 == side2 || side2 == side3 || side3 == side1)
+ printf("\nEntered triangle is a ISOSCELES triangle.");
+ else
+ printf("\nEntered triangle is NOT a ISOSCELES triangle.");
+ // equilateral check
+ if (side1 == side2 && side2 == side3)
+ printf("\nEntered triangle is a EQUILATERAL triangle.");
+ else
+ printf("\nEntered triangle is NOT a EQUILATERAL triangle.");
+ // scalene check
+ if (side1 != side2 && side2 != side3)
+ printf("\nEntered triangle is a SCALENE triangle.");
+ else
+ printf("\nEntered triangle is NOT a SCALENE triangle.");
+ // right-angle check
+ if (fabs(((side1 * side1) + (side2 * side2)) - (side3 * side3)) < EPSILON ||
+ fabs(((side2 * side2) + (side3 * side3)) - (side1 * side1)) < EPSILON ||
+ fabs(((side3 * side3) + (side1 * side1)) - (side2 * side2)) < EPSILON)
+ printf("\nEntered triangle is a RIGHT-ANGLED triangle.");
+ else
+ printf("\nEntered triangle is NOT a RIGHT-ANGLED triangle.");
+ return 0;
+}+
\ No newline at end of file
