Giving all details of Triangle given the lengths of its sides in c++

by Adarsh Ramamurthy

Gives various details like the angles, whether the triangle can be formed or not, circum radius, etc. The input here is the length of the sides of the triangle. Based on these facts the program does a series of calculations. And it calculates weather a triangle can be formed by those sides. If it can be formed the program also tells the type of triangle that can be formed.

#include<stdio.h><br /> #include<conio.h><br /> #include<stdlib.h><br /> #include<math.h></p> <p>main()<br /> {<br /> clrscr();<br /> float a,b,c,S,D,A,B,C,Area,R;<br /> printf(“Enter the lengths of the three sides of the triangle :</p> <p>“);<br /> scanf(“%f%f%f”,&a,&b,&c);</p> <p> S = (a+b+c)/2.0; // S is the semiperimeter of the triangle<br /> D = S*(S-a)*(S-b)*(S-c);//D is the square of the area of the triangle<br /> if(D<=0)<br /> {<br /> printf(”<br /> The triangle cannot be formed”);<br /> getch();<br /> exit(0);<br /> }</p> <p> if((a==b || b==c || c==a) && !(a==b && b==c && c==a))<br /> // this complex logic is to eliminate interpretting a triangle with all<br /> three<br /> // sides equal as both isosceles and equilateral.<br /> printf(”<br /> The triangle is ISOSCELES</p> <p>“);<br /> if(a==b && b==c && c==a)<br /> printf(”<br /> The triangle is EQUILATERAL</p> <p>“);<br /> if(a!=b && b!=c && c!=a)<br /> printf(”<br /> The triangle is SCALENE</p> <p>“);</p> <p> Area = sqrt(D);<br /> R = (a*b*c)/(4.0*Area);<br /> printf(“PERIMETER = %.2f units<br /> “,(2.0*S));<br /> printf(“AREA = %.2f sq.units<br /> “,Area);<br /> printf(“CIRCUM RADIUS = %.2f units<br /> “,R);<br /> // using sine rule,we get…<br /> A = (180.0/3.1415926)*asin(a/(2.0*R));// value of pi should be upto 7<br /> B = (180.0/3.1415926)*asin(b/(2.0*R));// decimal places of accuracy and<br /> also<br /> C = (180.0/3.1415926)*asin(c/(2.0*R));// note that the 7th decimal place<br /> is<br /> // 6 and not 7 as it had to be if were<br /> if(A==90.0 || B==90.0 || C==90.0) // approximated to 7 decimal<br /> places<br /> printf(”<br /> The triangle is RIGHT ANGLED<br /> “);<br /> if(A<90.0 && B<90.0 && C<90.0)<br /> printf(”<br /> The triangle is ACUTE ANGLED<br /> “);<br /> if(A>90.0 || B>90.0 || C>90.0)<br /> printf(”<br /> The triangle is OBTUSE ANGLED<br /> “);</p> <p> printf(”<br /> The angles are as follows :</p> <p>“);<br /> printf(“A = %.2f degrees<br /> “,A);<br /> printf(“B = %.2f degrees<br /> “,B);<br /> printf(“C = %.2f degrees<br /> “,C);<br /> printf(”<br /> Where A,B,C stand for angles opposite to sides<br /> %.2f,%.2f,%.2f”,a,b,c);<br /> printf(” respectively<br /> “);</p> <p> getch();<br /> return 0;<br /> }