The sum of the interior angle of a polygon with 10 sides is equal to 1440°
If it can be expressed as 360n, then n is
[tex]\begin{gathered} 360n=1440 \\ \\ \text{Divide both sides by 360} \\ \frac{360n}{360}=\frac{1440}{360} \\ \frac{\cancel{360}n}{\cancel{360}}=\frac{1440}{360} \\ n=4 \\ \\ \text{Therefore, }n\text{ is equal to }4 \end{gathered}[/tex]