Angle of view camera–subject distance to preserve the size of a subject, changing the angle of view can indirectly distort perspective, changing the apparent relative size of the subject and foreground. If the subject image size remains the same, then at any given aperture all lenses, wide angle and long lenses, will give the same depth of field. An example of how lens choice affects angle of view. This table shows the diagonal, horizontal, and vertical angles of view, in degrees, for lenses producing rectilinear images, when used with 36 mm × 24 mm format (that is, 135 film or full-frame 35mm digital
Angle trisection equation with real coefficients can be solved geometrically with compass, straightedge, and an angle trisector if and only if it has three real roots. A regular polygon with "n" sides can be constructed with ruler, compass, and angle trisector if and only if formula_63 where "r, s, k" ≥ 0 and where the "p" are distinct primes greater than 3 of the form formula_64 (i.e. Pierpont primes greater than 3). For any nonzero integer , an angle of measure radians can be divided into equal parts with straightedge and compass if and only if is either a power of or