Now find the quadrilateral (four-sided polygon). Repeat the experiment you did for the triangle. (Note: D not move any vertex over a side of the polygon, as this will fundamentally change the polygon). 3. What is the sum of the interior angles of the quadrilateral?

Did you know that the sum of the interior angles of any quadrilateral is always 360 degrees? This can be derived from the fact that a quadrilateral can be divided into two triangles. Since each triangle has a sum of interior angles equal to 180 degrees, combining them gives us 180 + 180 = 360 degrees for the quadrilateral! In practical terms, understanding the angle sum property of quadrilaterals is crucial for various fields, such as architecture and graphic design. For instance, when designing a room or a building, knowing that the angles must add up to 360 degrees helps ensure stability and functionality. So the next time you're working on designs, remember: it's all about those angles!