It is given in the question that,
A triangle with a perimeter of 66 inches has one side that is 16 inches long. the length of the other two sides have a ratio of 2:3.
Let the other two sides are of length 2x and 3x respectively .
And perimeter is the sum of the lengths of all three sides, that is
![16+2x+3x =66 \\ 16+5x = 66 \\ 5x = 50 \\ x =10](https://img.qammunity.org/2019/formulas/mathematics/high-school/a4vi1v6vkz0fuu5y97a18nf8wmm7d36zrq.png)
So the other two sides are
![2*10, 3*10 \\ 20, 30](https://img.qammunity.org/2019/formulas/mathematics/high-school/1590ufys8dy7c63v0lzemz6b0ucs0xtrej.png)
And the length of the longest side is 30 inches .