The formula for the measure of each interior angle of a regular polygon is given by:

\(\text{Interior Angle} = \frac{(n-2) \times 180}{n}\)

where `n` is the number of sides. Given that each interior angle is 144°, we can set up the equation:

\(144 = \frac{(n-2) \times 180}{n}\)

Solving this equation for `n` gives:

\(144n = (n - 2) \times 180\)
\(144n = 180n - 360\)
\(36n = 360\)
\(n = 10\)

So, the polygon has 10 sides.