Given,
The perimeter of the triangle, p=17 inches
Length of the 1st side of the triangle, a=5 inches
The length of the other side of the triangle, b=4 inches.
Let the other side of the triangle be c.
The perimeter of the triangle is given by,
![p=a+b+c](https://img.qammunity.org/2023/formulas/physics/college/yj8k6kgf37j8cb07sgys40nxkcgod7vpqw.png)
Therefore the value of the third side, c can be calculated as,
![c=p-a-b](https://img.qammunity.org/2023/formulas/physics/college/gkhl657e3r8dtpdyizynv508fi24b9dlkl.png)
On substituting the known values in the above equation,
![c=17-5-4=8\text{ inches}](https://img.qammunity.org/2023/formulas/physics/college/ygqsuu35tes8kiaqpq1viec40v0ivnxo4l.png)
Therefore, the length of the third side is 8 inches.
And the correct answer is option B.