Exterior angle theorem sum of angles of a triangle is 180°. If it is known that the sum of the measures of the angles in a triangle is 180°, then the HSEAT is proved as follows: On the other hand, if the HSEAT is taken as a true statement then: Proving that the sum of the measures of the angles of a triangle is 180°. The Euclidean proof of the HSEAT (and simultaneously the result on the sum of the angles of a triangle) starts by constructing the line parallel to side "AB" passing through point "C" and then using the properties of
Zero degrees of freedom Zero degrees of freedom In statistics, the non-central chi-squared distribution with zero degrees of freedom can be used in testing the null hypothesis that a sample is from a uniform distribution on the interval (0, 1). This distribution was introduced by Andrew F. Siegel in 1979. The chi-squared distribution with "n" degrees of freedom is the probability distribution of the sum where However, if and formula_4 are independent, then the sum of squares above has a non-central chi-squared distribution with "n" degrees of freedom and "noncentrality parameter" It is trivial that a "central" chi-square distribution with zero degrees of freedom