Meaning of Oblique Projection
Oblique drawing is also a pictorial method of drawing. In oblique projection, the object is drawn with one of its faces true to dimensions i.e. a face is parallel to the horizontal plane.
The receding lines (oblique lines) may be drawn at angles 30°, 45°, or 60°, but 45° angle is mostly used.
One disadvantage of oblique drawing is that it distorts the drawing and can never look natural. Therefore, in order to prevent this distortion, the receding axes (widths) are usually drawn half-size.