Answer :
Answer:
The value of RD' is 5 units.
Step-by-step explanation:
It is given that rectangle ABCD was dilated to create rectangle A'B'C'D' using point R as the center of dilation.
The scale factor is the proportion of side length of image and side length of preimage.
[tex]k=\frac{\text{lenght of image}}{\text{lenght of preimage}}[/tex]
[tex]k=\frac{B'C'}{BC}[/tex]
[tex]k=\frac{4}{12}[/tex]
[tex]k=\frac{1}{3}[/tex]
Scale factor is also defined as
[tex]k=\frac{RD'}{RD}[/tex]
[tex]\frac{1}{3}=\frac{RD'}{15}[/tex]
Multiply both sides by 15.
[tex]RD'=5[/tex]
Therefore the value of RD' is 5 units.