I've always been kind of confused by shearing, so I'll briefly describe its basics. Shearing is a linear transformation that displaces a coordinate in a fixed direction, by an exact amount that is proportional to the signed distance from its parallel (going through the origin). Importantly, shearing is not a rotation. It simply changes all the angles between and the length of line segments that are not parallel to the displacement. Interestingly, shearing preserves the area of geometric figures and relative distances of collinear points.
I've always been kind of confused by shearing, so I'll briefly describe its basics. Shearing is a linear transformation that displaces a coordinate in a fixed direction, by an exact amount that is proportional to the signed distance from its parallel (going through the origin). Importantly, shearing is not a rotation. It simply changes all the angles between and the length of line segments that are not parallel to the displacement. Interestingly, shearing preserves the area of geometric figures and relative distances of collinear points.