1. The problem asks for the sum of the interior angle measures of a quadrilateral. 2. The formula for the sum of interior angles of any polygon with $n$ sides is: $$\text{Sum of interior angles} = (n - 2) \times 180$$ 3. For a quadrilateral, $n = 4$. Substitute this into the formula: $$\text{Sum} = (4 - 2) \times 180 = 2 \times 180$$ 4. Calculate the product: $$2 \times 180 = 360$$ 5. Therefore, the sum of the interior angles of the quadrilateral is $360$ degrees. This means if you add up all four interior angles of the quadrilateral, the total will always be $360$ degrees.