Problem IV
To Find the Dividing-Points of a Given Horizontal Line
Let the horizontal line A B (Fig. 15.) be given in position and magnitude. It is required to find its dividing-points.
Find the vanishing-point V of the line A B.
With center V and distance V T, describe circle cutting the sight-line in M and N.
Then M and N are the dividing-points required.
In general, only one dividing-point is needed for use with any vanishing-point, namely, the one nearest S (in this case the point M). But its opposite N, or both, may be needed under certain circumstances.