Octadecagon Octadecagon An octadecagon (or octakaidecagon) or 18-gon is an eighteen-sided polygon. A "regular octadecagon" has a Schläfli symbol {18} and can be constructed as a quasiregular truncated enneagon, t{9}, which alternates two types of edges. As 18 = 2 × 3, a regular octadecagon cannot be constructed using a compass and straightedge. However, it is constructible using neusis, or an angle trisection with a tomahawk. The following approximate construction is very similar to that of the enneagon, as an octadecagon can be constructed as a truncated enneagon. It is also feasible with exclusive use of compass and straightedge. The "regular
Sides of an equation it, and still remain a solution. For example in mathematical physics, the homogeneous equation may correspond to a physical theory formulated in empty space, while the inhomogeneous equation asks for more 'realistic' solutions with some matter, or charged particles. More abstractly, when using infix notation the term "T" stands as the left-hand side and "U" as the right-hand side of the operator *. This usage is less common, though. Sides of an equation In mathematics, LHS is informal shorthand for the left-hand side of an equation. Similarly, RHS is the right-hand side. The two sides have the same value, expressed