Information given
The perimeter of a triangle is 49 ft
And let's the 3 sides of the triangle A, B and C. From the info given we know:
[tex]A+B+C=\text{ 49 }[/tex]
And we also know some conditions given by: (Side B is 3 ft shorter than A)
[tex]B=\text{ A-3 }[/tex]
Side C is twice the lenght of A:
[tex]C=\text{ 2A}[/tex]
Now we can replace in the first equation the conditions and we have:
[tex]A\text{ + (A}-3\text{) +2A = 49}[/tex]
Now we can do some algebra:
[tex]A\text{ +A +2A }-3\text{ = 49}[/tex][tex]4A=\text{ 52 }\leftrightarrow\text{ A= }\frac{52}{4}=13[/tex][tex]B=\text{ A}-3=\text{ 13}-3=\text{ 10, C = 2A =2}\cdot13=26\text{ }[/tex]
The only possibility that makes sense from the options given is:
13
