HP Prime Graphing Wireless Calculator - Manual (Page 38)

34 Geometry
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 ,
tap Transform, 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.
Rotation A rotation is a mapping that
rotates each point by a fixed
angle around a center point.
The angle is defined using
the angle() command,
with the vertex of the angle
as the first argument.
Suppose you wish to rotate
the square (GC) around point K (GK) through
∡
LKM in the
figure to the right.
1. Tap ,
tap Transform, and select Rotation.
rotation() appears on the entry line.
2. Between the
parentheses, enter:
GK,angle(GK,GL,GM
),GC
3. Press E or tap
.