Incircle and excircles of a triangle polygon with any number of sides that has an inscribed circle—one that is tangent to each side—is called a tangential polygon. Incircle and excircles of a triangle In geometry, the incircle or inscribed circle of a triangle is the largest circle contained in the triangle; it touches (is tangent to) the three sides. The center of the incircle is a triangle center called the triangle's incenter. An excircle or escribed circle of the triangle is a circle lying outside the triangle, tangent to one of its sides and tangent to the extensions of the other two. Every triangle has three
When a white horse is not a horse be found in the widely known "Happiness of Fish" dialogue in "Zhuangzi" (17, tr. Watson 1968:188-9). Huizi says "You're not a fish [子非魚] — how do you know what fish enjoy?" (denying that Zhuangzi is a member of the class of fish) and Zhuangzi replies "You're not I [子非我], so how do you know I don't know what fish enjoy?" (denying that the individuals Huizi and Zhuangzi are identical). Beyond the inherent semantic ambiguities of "Baima fei ma", the first line obscurely asks "ke hu" "Can it be that …?". This dialogue could be an attempted proof that a white