#### Basic geometric terms

Point

an exact location in space

Line

A collection of an infinite number of points in a straight pathway with unlimited length and having no width.

Plane

a flat surface that has no thickness and extends forever

parallel lines

Coplanar lines that do not intersect. Their slopes are equal.

transformations

scaling, rotation, shearing (skewing), and reflecting (flipping) objects to change their appearance.

reflections

flipping motions

Reflections Across Parallel Lines

A composition of reflections across two parallel lines is a translation

Reflections across intersecting lines

A composition of reflections across two intersecting lines is a rotation

reflections across perpendicular lines

A reflection across perpendicular lines results in a rotation of the original figure.

translation

Sliding all the points of a shape according to given directions (up/down, right / left)

glide reflection

the composition of a translation followed by a reflection in a line parallel to the translation vector

Pre-image

the original figure

image

The transformed figure

Rotation

The spinning motion of shape on its axis