In learner-centred methods, the teacher/instructor is both a teacher and a learner at the same time. In the words of Lawrence Stenhouse, the teacher plays a dual role as a learner as well âso that in his classroom extends rather than constricts his intellectual horizonsâ.
Two-point perspective has one set of lines parallel to the picture plane and two sets oblique to it. Parallel lines oblique to the picture plane converge to a vanishing point, which means that this set-up will require two vanishing points. Walls in 2-point perspective, converging toward two vanishing points.
Geometric Series Convergence. The geometric series is given by. a rn = a + a r + a r2 + a r3 + ... If |r| < 1 then the following geometric series converges to a / (1 - r). If |r| >= 1 then the above geometric series diverges.