HP Prime Graphing NW280AAABA manual Tap Select Reflection, Symmetry axis defined in step

Reflection	A reflection is a
	transformation which maps
	an object or set of points
	onto its mirror image, where
	the mirror is either a point or
	a line. A reflection through a
	point is sometimes called a
	half-turn. In either case, each
	point on the mirror image is the same distance from the mirror
	as the corresponding point on the original. In the example at
	the right, the original triangle D is reflected through point I.
	1.	Tap	and select Reflection.
	2. Tap the point or straight object (segment, ray, or line) that
		will be the symmetry axis (that is, the mirror) and press
		E.
	3. Tap the object that is to be reflected across the symmetry
		axis and press E. The object is reflected across the
		symmetry axis defined in step 2.
Dilation	A dilation (also called a homothety or uniform scaling) is a
	transformation where an object is enlarged or reduced by a
	given scale factor around a given point as center.
	In the illustration at the right,
	the scale factor is 2 and the
	center of dilation is
	indicated by a point near the
	top right of the screen
	(named I). Each point on the
	new triangle is collinear with
	its corresponding point on
	the original triangle and point I. Further, the distance from
	point I to each new point will be twice the distance to the
	original point (since the scale factor is 2).
	1.	Tap	and select Dilation.

2. Tap the point that is to be the center of dilation and press E.

3. Enter the scale factor and press E.

4. Tap the object that is to be dilated and press E.

162 Geometry