Since the reflected wave and the incident wave add to each other while moving in opposite directions, the appearance of propagation is lost and the resulting vibration is called a standing wave. When sound waves in air (pressure waves) encounter a hard surface, there is no phase change upon reflection. That is, when the high pressure part of a sound wave hits the wall, it will be reflected as a high pressure, not a reversed phase which would be a low pressure.
A principal diagonal of a hexagon is a diagonal which divides the hexagon into quadrilaterals. In any convex equilateral hexagon (one with all sides equal) with common side a, there exists a principal diagonal d 1 such that.
So you take half of the total, meaning 14 diagonals. I checked to make sure this process worked with the other polygons. The hexagon had 6 vertices with 3 diagonals which gives you 18 divided by 2 equals 9 diagonals. I tested the others and this method worked. I also noticed a pattern between the number of sides and how many diagonals came from each vertex. The pentagon had 2, hexagon 3, heptagon 4, and if the pattern continues the octagon has 5.