Preparing for the Regents Examination Geometry, AK

20
y x 2
6
5
4
3
2
1
y
y x
65 4 3 2 1
1
2
3
4
5
6
1 2 3 4 5 6
x y 2
6-4 Point Reflection and
Symmetry
(pages 103–104)
1 (2) H
2 (1) only line symmetry
3 (3) both point and line symmetry
4 (3) (k, 2k)
5 line symmetry
6 both
7 point symmetry
8 both
9 (1, 3)
10 (3, 1)
11 (9, 0)
12 (2, 6)
13 (4, 4)
14 (8, 2)
15 (2, 4)
16 (2, 8)
17 (10, 10)
18 Point reflection is a transformation of a
figure into another figure.
Point symmetry is a quality of a figure. A figure
with point symmetry is not changed by a
reflection through that point. (It is rotated in
either direction 180 about a point.)
x
6-5 Rotations
(page 107)
1 (2) trapezoid
2 (1) regular hexagon
3 (2) regular pentagon
4 (2) rectangle
5 (1) equilateral triangle
6 (1)
7 Z
8 X
9 Y
10 Z
11 (1, 5)
12 (3, 3)
13 (2, 8)
14 (2, 3)
15 (2, 2)
16 (4, 4)
17 (6, 3)
18 (2, 6)
19 (5, 5)
20 W(3, 2), H(8, 2), Y(5, 10)
6-6 Dilations
(page 110)
1 (3) (4, 10)
2 (2) 1 _
2
3 (4) (x, y) → (2x, 2y)
4 (4) 20 square inches
5 (6, 9)
9
6 ( 3, _
2 ) or (3, 4.5)
7 (4, 6)
For problems 8–11, see figure below.
8 A(0, 8), B(2, 2), C(6, 4)
9 A(0, 3), B ( 3 _ ,
4 3 _
4 ) , C ( 2
1 _ , 1
4 1 _
2 )
10 A(0, 12), B(3, 3), C(9, 6)
6-6 Dilations 31