This geometry video tutorial explains how to calculate the number of diagonals in a regular polygon such as a square, pentagon, hexagon, heptagon, and an octagon. It also explains how to confirm the answer by drawing the diagonals in a regular polygon. In addition, it discusses how to determine the type of polygon given the number of diagonals as well as the sum of the interior angles of a polygon and the measure of each interior angle and exterior angle. Polygons: https://www.youtube.com/watch?v=E_-3ulbtcLk Angles of Regular Polygons: https://www.youtube.com/watch?v=OEzEo4XqzJQ Quadrilaterals: https://www.youtube.com/watch?v=ogcH3eM5beM Parallelograms: https://www.youtube.com/watch?v=t42sLuns4Qs Rectangles - Special Quadrilaterals: https://www.youtube.com/watch?v=Ov4aTty67A8 Isosceles Trapezoids: https://www.youtube.com/watch?v=AlyWS8bG3kE _________________________________ The Rhombus: https://www.youtube.com/watch?v=uXo_Vpctmrg Kites: https://www.youtube.com/watch?v=UTgF6lSAMa8 Proving Parallelograms: https://www.youtube.com/watch?v=MQJnPfNb2Og Proving a Quadrilateral Is a Kite: https://www.youtube.com/watch?v=dh8vRzTNVBg Proving a Quadrilateral Is a Rhombus: https://www.youtube.com/watch?v=EtoP5G98sok __________________________________ Proving Isosceles Trapezoids: https://www.youtube.com/watch?v=EvTHRcNBAc8 2 Column Proofs - Quadrilateral: https://www.youtube.com/watch?v=m8BlpR7xhiM Skew Lines: https://www.youtube.com/watch?v=cemF45vNOhg Points, Lines, Planes, & Segments: https://www.youtube.com/watch?v=dDWjhRfBsKM _______________________________________ Final Exams and Video Playlists: https://www.video-tutor.net/ Full-Length Videos and Worksheets: https://www.patreon.com/MathScienceTutor/collections