What is the sum of the interior angles of a quadrilateral?

The sum of the interior angles of a quadrilateral is 360 degrees. This can be determined using the formula for the sum of the interior angles of a polygon, which is calculated as (n - 2) × 180 degrees, where n is the number of sides. For a quadrilateral, n equals 4. The calculation would therefore be (4 - 2) × 180 = 2 × 180 = 360 degrees.

This concept is crucial in understanding the properties of polygons, as it helps to confirm the geometric principles that apply to various shapes. The knowledge of interior angles is foundational when studying more complex geometric figures and is commonly applied in many areas of mathematics and real-world scenarios, such as architecture and engineering.