Hyperbolic geometry or hypercycle, then the triangle has no circumscribed circle. As in spherical and elliptical geometry, in hyperbolic geometry if two triangles are similar, they must be congruent. A special polygon in hyperbolic geometry is the regular apeirogon, a uniform polygon with an infinite number of sides. In Euclidean geometry, the only way to construct such a polygon is to make the side lengths tend to zero and the apeirogon is indistinguishable from a circle, or make the interior angles tend to 180 degrees and the apeirogon approaches a straight line. However, in hyperbolic geometry, a regular apeirogon has sides of
ILR scale are able to perform most basic functions using the language; this includes buying goods, reading the time, ordering simple meals and asking for minimal directions Limited working proficiency is rated 2 on the scale. A person at this level is described as follows: Professional working proficiency is rated 3 on the scale. Level 3 is what is usually used to measure how many people in the world know a given language. A person at this level is described as follows: Individuals classified at level 3 are able to use the language as part of normal professional duties and can reliably