Search results
Results from the WOW.Com Content Network
The side view is an isosceles trapezoid. In first-angle projection, the front view is pushed back to the rear wall, and the right side view is pushed to the left wall, so the first-angle symbol shows the trapezoid with its shortest side away from the circles.
Discard the triangle if matrix M contained an odd number of reflections (facing the opposite way of the unit triangle) | | < The unit triangle is used as a reference and transformation M is used as a trace to tell if vertex order is different between two triangles. The only way vertex order can change in two dimensions is by reflection.
It is always possible to partition a concave polygon into a set of convex polygons. A polynomial-time algorithm for finding a decomposition into as few convex polygons as possible is described by Chazelle & Dobkin (1985). [5] A triangle can never be concave, but there exist concave polygons with n sides for any n > 3.
The 42 possible triangulations for a convex heptagon (7-sided convex polygon). This number is given by the 5th Catalan number . It is trivial to triangulate any convex polygon in linear time into a fan triangulation , by adding diagonals from one vertex to all other non-nearest neighbor vertices.
A rectilinear polygon has corners of two types: corners in which the smaller angle (90°) is interior to the polygon are called convex and corners in which the larger angle (270°) is interior are called concave. [1] A knob is an edge whose two endpoints are convex corners. An antiknob is an edge whose two endpoints are concave corners. [1]
Polygons with only one concave vertex can always be fan triangulated, as long as the diagonals are drawn from the concave vertex. It can be known if a polygon can be fan triangulated by solving the Art gallery problem, in order to determine whether there is at least one vertex that is visible from every point in the polygon.
Secondly, each of these triangles can be transformed into a right triangle and subsequently into a rectangle with one side of length 1. Alternatively, a triangle can be transformed into one such rectangle by first turning it into a parallelogram and then turning this into such a rectangle. By doing this for each triangle, the polygon can be ...
Kanizsa triangle: The Kanizsa triangle is an optical illusion first described by the Italian psychologist Gaetano Kanizsa in 1955. It is a triangle formed of illusory contours. Kinetic Depth Effect: The Kinetic depth effect is the phenomenon whereby the three-dimensional structural form of a silhouette can be perceived when the object is moving ...