Equilateral polygon with 60° internal angles. An equilateral quadrilateral is called a rhombus, an isotoxal polygon described by an angle α. It includes the square as a special case. A convex equilateral pentagon can be described by two angles α and β, which together determine the other angles. Concave equilateral pentagons exist, as do concave equilateral polygons with any larger number of sides. An equilateral polygon which is cyclic (its vertices are on a circle) is a regular polygon (a polygon that is both equilateral and equiangular). A tangential polygon (one that has an incircle tangent to all its sides) is equilateral
Gewehr 98 internal magazine boxes feature an internal magazine length of to store maximal overall length 7.92×57mm Mauser cartridges without dimensional issues. The cartridges are stored in the magazine box in a staggered column at a stacking angle of 30 degrees, so viewed from the end, three cartridges touching each other form the points of an equilateral triangle. The magazine can be loaded with single rounds by pushing the cartridges into the receiver top opening or via stripper clips. Each stripper clip can hold 5 rounds to fill the magazine and is inserted into clip guides machined into the rear receiver bridge.