Question

PLEASE HELP!! I do not understand this. And can you explain it for me when I use it again?

Answer 1

Let's start b writing down coordinates of all points:
A(0,0,0)
B(0,5,0)
C(3,5,0)
D(3,0,0)
E(3,0,4)
F(0,0,4)
G(0,5,4)
H(3,5,4)

a.) When we reflect over xz plane x and z coordinates stay same, y coordinate  changes to same numerical value but opposite sign. Moving front-back is moving over x-axis, moving left-right is moving over y-axis, moving up-down is moving over z-axis.

A(0,0,0)
Reflecting
A(0,0,0)

B(0,5,0)
Reflecting
B(0,-5,0)

C(3,5,0)
Reflecting
C(3,-5,0)

D(3,0,0)
Reflecting
D(3,0,0)


b.)
A(0,0,0)
Moving
A(-2,-3,1)

B(0,-5,0)
Moving
B(-2,-8,1)

C(3,-5,0)
Moving
C(1,-8,1)

D(3,0,0)
Moving
D(1,-3,1)