Central angle of a circle

The central angle of a circle determined by two radii and an arc joining them, all of the same length. A circle is comprised of 2jr radians. The action of moving back and forth alternately. 

A central angle of a circle is an angle that has its vertex at the center and that has sides that are radii. 

Radian Measure System for measuring angles in which one radian is the measure of a central angle of a circle that intercepts an arc equal in length to the radius of the circle. 

A sector of a circle is a region contained within the interior of a central angle and arc. 

The area of a sector is found in a similar way to finding the length of an arc. To find the area of a sector, simply multiply the area of a circle, nr2, by the fraction 3f 0, again using x as the degree measure of the central angle. Example ... 

The oxygen atoms are coplanar (they lie in the same plane and the apex of C-O-C angle is centrally directed in the same plane) and they are symmetrically evenly spaced in a circle). 

The projection of the net of latitude and longitude lines of the reference sphere upon a plane forms a stereographic net—the Wulff net (Fig. 4). The angles between any two points can be measured with this net by bringing the points on the same great circle and counting their difference in latitude keeping the center of the projection at the central point of the Wulff net. 

The partial wave sum is now reduced to a sum over few pole contributions in the complex plane of /.. The contribution of a single pole to the phase shift function and the deflection function can be obtained from the parameterization (55). Fig. 10 illustrates the result. (/) is essentially a pulse centred at / = Re (Xp — ) with the depth 2/Im Xp and the width 2 Im Xp. Now one proceeds as follows. Starting with N poles, which are placed on a small circle centred at 7.p in the complex /-plane, the number of these poles (N) and the real and imaginary part of the central pole (/p) are derived from semiclassical quantities. The rainbow angle is given by 9r = 2N/lm Xp,... 

The fraction of the Earth s surface area covered by the satellite within a circle for a given elevation angle el and the corresponding Earth central angle y is... 

Fig. 5. Various parameters of accessibility, twist, and bend plotted vs. sequence number. Part 1 (a) Solvent-accessible area of side chains, (b) Fractional accessibility (referred to full sphere) of backbone carbonyl oxygen and peptide nitrogen. The separate plot for values less than 1% is meant to show that no accessibility was detected for many atoms. The actual nonzero values are not to be taken too literally. Part 2 (c) Backbone angles as normally defined, (d) Angles between sequentially adjacent carbonyl vectors in the backbone plotted between the sequence numbers of the two residues involved. Part 3 (e) Distance in A between the tips, T, of adjacent residues as defined in the text, (f) Distances in A between peptide center, M, and the third sequential peptide center (open circles), and between carbon a and the sixth sequential a-carbon (crosses) plotted opposite the central carbon atom in each case, (g) Angles between lines joining the centers of successive peptide bonds plotted between the residues defining the central bond, (h) Angles between lines joining successive a carbons plotted opposite the central carbon, (Note that the accessibilities were calculated with coordinate set 4 and the other parameters with set 6 see text.)...

Fig. 10.3. Rotational FC factors f(j) as defined in (10.3a) for the first three bending states of H2O in the electronic ground state (open circles). The filled circles represent the results of the harmonic oscillator approximation, i.e., the right-hand side of (10.7) without the sinusoidal term, k is the bending quantum number. The insets depict the squares of the corresponding bending wavefunc-tions as functions of the HOH bending angle a. Because of the heavy central atom the bending angle a and the Jacobi angle 7 are almost identical for H2O. Adapted from Schinke, Vander Wal, Scott, and Crim (1991).

Benzanthracene is still colourless and less reactive than anthracene. Benzotetracene is pale yellow and benzopentacene is violet red. These hydrocarbons are all less reactive than the parent hydrocarbons. The benzenoidity must be inherent in the circle. In the angle where the two arrows meet, a new sextet, an induced one, is formed by the contribution of 2 IT electrons each from the neighbouring rings and the inherent double bond of the central ring. 

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