SSS Triangle functions, need output help

My function is outputting ang1, ang2, and ang3 in addition to my fprintf statements, why? and how to i fix it? Question asks for my to calculate it the triangle is valid by checking the area.

function [ang1 ang2 ang3 ] = triangle(s1,s2,s3)
%TRIANGLE calculates the degrees of all angles given the length of all
%sides.;
s1=input('Please input side 1: ');
s2=input('Please input side 2: ');
s3=input('Please input side 3: ');
s=(s1+s2+s3)/(2);
Area=sqrt(s*(s-s1)*(s-s2)*(s-s3));
if Area > 0
ang1=acosd((s2^2 + s3^2 - s1^2)/(2*s2*s3));
ang2=acosd((s3^2 + s1^2 - s2^2)/(2*s3*s1));
ang3=acosd((s1^2 + s2^2 - s3^2)/(2*s1*s2));
    fprintf('The angle opposite side 1 is %.2f deg\n',ang1);
    fprintf('The angle opposite side 2 is %.2f deg\n',ang2);
    fprintf('The angle opposite side 3 is %.2f deg\n',ang3);
elseif Area >= 0
    fprintf('The 3 sides do NOT form an open triangle!\n');
end
end

I'm also having a problem with triangle inputs (1,2,3), it says the correct thing but outputs an error with it

Error in ==> triangle at 5
s1=input('Please input side 1: ');

??? Output argument "ang1" (and maybe others) not
assigned during call to "P:\triangle.m>triangle".

do the input statements need to be outside the function?

FINAL SOLUTION:

function [ang1 ang2 ang3]=triangle(s1,s2,s3)
%TRIANGLE calculates the degrees of all angles given the length of all
%sides.;
ang1=acosd((s2^2 + s3^2 - s1^2)/(2*s2*s3));
ang2=acosd((s3^2 + s1^2 - s2^2)/(2*s3*s1));
ang3=acosd((s1^2 + s2^2 - s3^2)/(2*s1*s2));
end

   %Test_triangle
  s1=input('Please input side 1: ');
  s2=input('Please input side 2: ');
  s3=input('Please input side 3: ');
  s=((s1+s2+s3)/(2));
  Area=sqrt(s*(s-s1)*(s-s2)*(s-s3));
  if Area > 0
        [ang1 ang2 ang3]=triangle(s1,s2,s3);
        fprintf('The angle opposite side 1 is %.2f deg.\n',ang1);
        fprintf('The angle opposite side 2 is %.2f deg.\n',ang2);
        fprintf('The angle opposite side 3 is %.2f deg.\n',ang3);
  elseif Area <= 0
        fprintf('The 3 sides do NOT form an open triangle!\n');
  end

Answer 1

[Chirag Gupta]

This is because your function defines them as output arguments

   function [ang1 ang2 ang3 ] = triangle(s1,s2,s3)

MATLAB expects 3 outputs as defined by ang1,ang2 and ang3. Thats why you get the error.

If you don't want the outputs, just define the function as:

 function triangle(s1,s2,s3)

[Chirag Gupta]

similarly if you don't want to supply inputs to the function you don't need to pass them as input args

function triangle()

% ......

s1 = input

etc

[Kyle]

I found out what was wrong, i miss read the question. I needed to create the function and then a test program to run it. My mistake. Thanks for the help.

Answer 2

[Walter Roberson]

You only define ang1, ang2, and ang3 if Area > 0. What happens if the Area is not greater than 0 ?

[Kyle]

Oh,typo.

Area <=0

fprintf('The 3 sides do NOT form an open triangle!\n');

But i dont understand how i can define the equations for ang1 ang 2 and ang3 without causing it to output them separate from the fprintf statements.

Answer 3

[Aqsa Saleem]

given triangle with sides a,b,c write a program to find whether it is an isosceles triangle in MATLAB programing