```11-5 Rotations on the Coordinate Plane
Determine whether each synchronized
swimming formation has rotational symmetry. If
it does, describe the angle of rotation.
ANSWER: Always; the original figure and the rotated image are
congruent. Since the corresponding side lengths are
equal, the perimeters are the same.
22. Triangle XYZ was rotated about the origin to
ΔX´Y´Z´. Which of the following describes the
rotation?
A 90° clockwise about the origin
B 90° counterclockwise about the origin
C 180° clockwise about the origin
D 270° clockwise about the origin
°
26. If m∠B = 17° and ∠A and ∠B are complementary,
find m∠A.
18. Reason Inductively Name a clockwise rotation that
is equivalent to a rotation of 90° counterclockwise about the origin.
For Exercises 28–30, use the diagram shown.
20. Construct an Argument Will a geometric figure
and its rotated image sometimes, always, or never
have the same perimeter? Explain your reasoning.
ANSWER: Always; the original figure and the rotated image are
congruent. Since the corresponding side lengths are
equal, the perimeters are the same.
22. Triangle XYZ was rotated about the origin to
ΔX´Y´Z´. Which of the following describes the
rotation?