What Is "direct Isometry"?

"Direct isometry" is defined as orientation being preserved, unlike opposite isometry, and the order of the lettering in both the image and figure are the same, either counterclockwise or clockwise. Direct isometry occurs in point reflection, translations and rotations, preserving midpoint, colinearity, parallelism, angle measure and distance properties.

Opposite isometry is reflected in line reflection, dilations and glide reflection. The same properties are preserved, except distance is not preserved with dilations. Also with dilations, the letter order is the same, which ironically is a characteristic of direct isometry. With glide reflection and line reflection, there is reverse orientation, which means the letter order is changed.