A 10-sided equilateral polygon is drawn. Investigate and identify a pattern to find the angle measure of one interior angle.

To find the angle measure of one interior angle of a regular polygon, we can use the formula:

\[
\text{Interior Angle} = \frac{(n - 2) \times 180^\circ}{n}
\]

where \( n \) is the number of sides of the polygon.

For a 10-sided polygon (decagon), we have \( n = 10 \). Plugging this value into the formula gives:

\[
\text{Interior Angle} = \frac{(10 - 2) \times 180^\circ}{10}
\]

Calculating the expression inside the parentheses:

\[
10 - 2 = 8
\]

Now multiplying by 180°:

\[
8 \times 180^\circ = 1440^\circ
\]

Now, divide by \( n = 10 \):

\[
\text{Interior Angle} = \frac{1440^\circ}{10} = 144^\circ
\]

Therefore, the measure of one interior angle of a regular 10-sided polygon is:

\[
\boxed{144^\circ}
\]