1. The problem asks for the sum of the interior angle measures of a five-sided polygon (pentagon). 2. The formula to find the sum of interior angles of any polygon with $n$ sides is: $$\text{Sum of interior angles} = (n - 2) \times 180$$ 3. For a pentagon, $n = 5$. Substitute this into the formula: $$\text{Sum} = (5 - 2) \times 180$$ 4. Simplify inside the parentheses: $$\text{Sum} = 3 \times 180$$ 5. Multiply to find the sum: $$\text{Sum} = 540$$ 6. Therefore, the sum of the interior angles of the pentagon is 540 degrees.