In plane geometry, an angle is the figure formed by two rays, called the sides of the angle, sharing a common endpoint, called the vertex of the angle. Angles formed by two rays lie in a plane. Angles are formed by the intersection of two planes in Euclidean and other spaces; these are called dihedral angles. Angles formed by the intersection of two curves in a plane are defined as the angle determined by the tangent rays at the point of intersection. Similar statements hold in space, for example, the spherical angle formed by two great circles on a sphere is the dihedral angle between the planes determined by the great circles. Angle is used to designate the measure of an angle or of a rotation; this measure is the ratio of the length of a circular arc to its radius. In the case of a geometric angle, the arc is delimited by the sides. In the case of a rotation, the arc is centered at the center of the rotation and delimited by any other point and its image by the rotation; the word angle comes from the Latin word angulus, meaning "corner".

Both are connected with the Proto-Indo-European root *ank-, meaning "to bend" or "bow". Euclid defines a plane angle as the inclination to each other, in a plane, of two lines which meet each other, do not lie straight with respect to each other. According to Proclus an angle must be a relationship; the first concept was used by Eudemus. In mathematical expressions, it is common to use Greek letters to serve as variables standing for the size of some angle. Lower case Roman letters are used, as are upper case Roman letters in the context of polygons. See the figures in this article for examples. In geometric figures, angles may be identified by the labels attached to the three points that define them. For example, the angle at vertex A enclosed by the rays AB and AC is denoted ∠BAC or B A C ^. Sometimes, where there is no risk of confusion, the angle may be referred to by its vertex. An angle denoted, say, ∠BAC might refer to any of four angles: the clockwise angle from B to C, the anticlockwise angle from B to C, the clockwise angle from C to B, or the anticlockwise angle from C to B, where the direction in which the angle is measured determines its sign.

However, in many geometrical situations it is obvious from context that the positive angle less than or equal to 180 degrees is meant, no ambiguity arises. Otherwise, a convention may be adopted so that ∠BAC always refers to the anticlockwise angle from B to C, ∠CAB to the anticlockwise angle from C to B. There is some common terminology for angles, whose measure is always non-negative: An angle equal to 0° or not turned is called a zero angle. Angles smaller than a right angle are called acute angles. An angle equal to 1/4 turn is called a right angle. Two lines that form a right angle are said to be orthogonal, or perpendicular. Angles larger than a right angle and smaller than a straight angle are called obtuse angles. An angle equal to 1/2 turn is called a straight angle. Angles larger than a straight angle but less than 1 turn are called reflex angles. An angle equal to 1 turn is called complete angle, round angle or a perigon. Angles that are not right angles or a multiple of a right angle are called oblique angles.

The names and measured units are shown in a table below: Angles that have the same measure are said to be equal or congruent. An angle is not dependent upon the lengths of the sides of the angle. Two angles which share terminal sides, but differ in size by an integer multiple of a turn, are called coterminal angles. A reference angle is the acute version of any angle determined by subtracting or adding straight angle, to the results as necessary, until the magnitude of result is an acute angle, a value between 0 and 1/4 turn, 90°, or π/2 radians. For example, an angle of 30 degrees has a reference angle of 30 degrees, an angle of 150 degrees has a reference angle of 30 degrees. An angle of 750 degrees has a reference angle of 30 degrees; when two straight lines intersect at a point, four angles are formed. Pairwise these angles are named according to their location relative to each other. A pair of angles opposite each other, formed by two intersecting straight lines that form an "X"-like shape, are called vertical angles or opposite angles or vertically opposite angles.

They are abbreviated as vert. opp. ∠s. The equality of vertically opposite angles is called the vertical angle theorem. Eudemus of Rhodes attributed the proof to Thales of Miletus; the proposition showed that since both of a pair of vertical angles are su

Koço Theodhosi

Koço Theodhosi was an Albanian politician of the Albanian Party of Labour. Theodhosi finished the French Lyceum of Korça, studied chemistry at the University of Lyon, at the University of Liège. During his studies he got into contact with French-speaking anti-fascist student group of the French Communist Party. Upon his return to Albania, he became involved in the anti-fascist movement. In 1936 he joined the Spanish Civil War as part of the international brigades. In April 1939, he was among the organizers of a student protest in Grenoble against the Italian invasion of Albania, it was an appeal to the French Prime Minister Edouard Daladier and the British Prime Minister Neville Chamberlain to gain support over the Italians. On 8 November 1941, Theodhosi was one of the 200 founding members of the Communist Party of Albania which would become the Party of Labour. During the Second World War, he participated as a partisan affiliated with the National Liberation Movement. In May 1944, he organized a Party Congress in Korçë.

He was among the 118 people comprising the Anti-Fascist Council of National Liberation Movement chosen in May 1944 by the Congress of Përmet. The Council acted as the transitional parliament, served the Communists in their plans to come to power. In 1944 Theodhosi was appointed by Enver Hoxha as Commissioner of Kuçovë and he served in this position until 1947. After that, he was Deputy Minister of Public Works, before being Deputy Chairman of the State Planning Commission in 1949, under Nako Spiru. In this capacity, he participated in delegations to the Soviet Union together with Hoxha. In 1950, Theodhosi was elected member of the People's Assembly, where he remained until 30 May 1975. Furthermore, he was for many years a member of the Central Committee of the Party. In 1954, he was appointed Minister of Industry in the government of Prime Minister Mehmet Shehu, before becoming Deputy Chairman of the Council of Ministers in 1955. At the 3rd Congress of the Party of Labourt of Albania in June 1956, he was elected candidate-member of its Politburo.

On 1 March 1959, he was appointed as Chairman of the State Planning Commission in the government of Prime Minister Shehu, held this function until 18 March 1966. At the same time, from 16 July 1962 to 18 March 1966, he served as Deputy Chairman of the Council of Ministers. In addition, on 1 January 1965 he was appointed as the successor of Adil Çarçani as Minister of Industry and held that office until 30 October 1974. During the 6th Congress of the Party in November 1971, he became member of the Politburo of the PPSh, a high-ranking position which he lost four years by his dismissal in September 1975. From 30 October 1974 to 1 September 1975, he served again as Minister of Industry and Mines in the government of Mehmet Shehu. After his dismissal in September 1975, he was succeeded by Pali Miska both as a member of the Politburo of the PPSh and as Minister of Industry and Mines. Theodhosi was arrested and instigated by the Minister of Interior Kadri Hazbiu, chief supervisor of the Sigurimi; the reasons for his dismissal were stated to be his errors in the construction of the hydroelectric power station of Fierza and the metallurgical complex near Elbasan.

An important additional reason for his overthrow was the accusation of military and economic conspiracy. Accused were other high-ranking military figures: Minister of Defence General Beqir Balluku, they all fell victim to the accusation of being too close to the Soviet Union, the Prime Minister of the People's Republic of China Zhou Enlai, Yugoslavia. In 1977, Theodhosi was executed, his son Arben Theodhosi, a painter with several exhibitions in Albania and abroad, had to interrupt his studies when he was detained for forced labor in one of the copper mines. Mehmet Shehu Petro Marko

Académie de Marseille

The Académie de Marseille the Académie des sciences, lettres et arts de Marseille, is a French learned society based in Marseille. It was founded in 1726 and includes those in the city involved in the arts and sciences; the Académie de Marseille was created by letters patent of Louis XV in August 1726, which stated in particular that the number of members would be limited to twenty. The founding document furthermore stated. However, the actual number of founding members was twenty-one, due to the insistence of Jean-Pierre Rigord that Henri de Belsunce be offered membership; this was rectified in 1730 when Joseph-Félix de Gravier resigned from the Académie and was not replaced. Dassy, Abbé. L'académie de Marseille, ses origines, ses publications, ses archives, ses membres. Barlatier-Feissat. Retrieved 2014-07-24. Académie de Marseille - official site