Question

1. Minh asks Marco to duplicate a graphic she has on her restaurant’s ceiling. The ceiling is covered with 1 ft by 1 ft tiles. A chandelier hangs in the center of the ceiling. The graphic Minh painted on the ceiling is a pentagon. Assuming that the chandelier is located at , the pentagon’s coordinates are A (-8,1) B (-9,3) C (-6,2) D (-3,5) E (-4,1

Minh wants to have the same graphic design duplicated in another location on the ceiling. She is considering four ideas.
(a) reflecting pentagon over the y-axis
a. Graph new pentagon when pentagon is reflected over the y-axis. What are the coordinates of pentagon ?
b. Write a math rule or explanation using words that describe a reflection of over the y-axis.
c. Using this rule, where would be located if reflected over the y-axis?
(b) rotating pentagon 90° clockwise about the origin
a. Graph the new pentagon when pentagon is rotated 90° clockwise about the origin. What

Answer 1

b] The rule represents the reflection over y-axis is given by:
(x,y)⇒(-x,y)

c]Using this rule, the image would be located onto the pre-image when reflected again. This implies that it will be mapped onto the original point.

d] When the new pentagon is rotated 90° clockwise, the new coordinates will be as follows:
the rule for this rotation is given by:
(x,y)⇒(-y,x)
thus using the above rule new coordinates will be:
A"(-1,8), B"(-3,9), C"(-2,6), D"(-5,3) and E"(-1,4). The new figure is shown in the graph.