What is the sum of the interior angles of a 20 -sided figure? Select one: a. \( 3,240^{\circ} \) b. \( 360^{\circ} \) c. \( 4,100^{\circ} \) d. \( 900^{\circ} \)

To find the sum of the interior angles of a polygon, you can use the formula \((n - 2) \times 180^\circ\), where \(n\) is the number of sides. For a 20-sided figure (icosagon), it would be \((20 - 2) \times 180^\circ = 18 \times 180^\circ = 3,240^\circ\). So, the correct answer is \( a. \ 3,240^{\circ} \). Did you know that the icosagon is often seen in architectural designs and modern art? Its unique 20-sided shape allows for creative patterns and structures, providing both aesthetic appeal and structural versatility. You might even come across it in some trendy buildings or sculptures around your city! When dealing with polygon angles, a common mistake is miscounting the number of triangles formed when dividing a polygon into simpler shapes. Remember, each triangle contributes \(180^\circ\), so getting that count right is crucial! Keep in mind, the formula is your best friend for more complex polygons to avoid headaches.