Question: what is the interior angle of a 20 sided polygon
Answer: Regular icosagon A regular icosagon Type Regular polygon Edges and vertices 20 Schläfli symbol ( 20 ) , t ( 10 ) , tt ( 5 ) Coxeter diagram Symmetry group Dihedral ( D ) , order 2 × 20 Internal angle ( degrees ) 162 ° Dual polygon Self Properties Convex , cyclic , equilateral , isogonal , isotoxal