It is the locus of points that are equidistant from a fixed point. In parametric, polar coordinate form, the points satisfy the equations:
x = r*cos(t)
y = r*sin(t)
where r is a positive constant (the radius) and 0 ≤ t < 2*pi radians.
The basic circular functions are sine, cosine and tangent. Then there are their reciprocals and inverses.
James E. Hall has written: 'Trigonometry; circular functions and their applications' -- subject(s): Plane trigonometry, Trigonometrical functions
Theta is the measure of the angle, whether in degrees or radians.
Trigonometry, triangle, times, ten, thousand . . . .
It is a semi-circular arc joining two diametrically opposite points on the sphere. These may be the "North" and "South" poles.
A circular based prism
circular wave
plane trigonometry spherical trigonometry
The main kinds are plane trigonometry and solid trigonometry. The latter will include trigonometry in hyper-spaces.
The formula for calculating centripetal acceleration in terms of the radius of the circular motion is a v2/r, where "a" represents the centripetal acceleration, "v" is the velocity of the object in circular motion, and "r" is the radius of the circle.
Hipparchus is the father of trigonometry.
It is a number - in trigonometry or elsewhere.