what is the angle of an octagon corner
Octagon A regular octagon is a closed figure with sides of the same length and internal angles of the same size. It has eight lines of reflective symmetry and rotational symmetry of order 8. A regular octagon is represented by the Schläfli symbol {8}. The internal angle at each vertex of a regular octagon is 135° (    3 π 4   {\displaystyle \scriptstyle {\frac {3\pi }{4}}}  radians). The central angle is 45° (    π 4   {\displaystyle \scriptstyle {\frac {\pi }{4}}}  radians).
Equilateral triangle In geometry, an equilateral triangle is a triangle in which all three sides are equal. In the familiar Euclidean geometry, equilateral triangles are also equiangular; that is, all three internal angles are also congruent to each other and are each 60Â°. They are regular polygons, and can therefore also be referred to as regular triangles.