Given:
Triangle ABC is similar to triangle XYZ.
The measures of the sides are AB = 6 cm, BC = 18 cm and XY = 12 cm
We need to determine the measure of side YZ.
Measure of YZ:
Since, ABC and XYZ are similar triangles, by using similar triangles property, we have;
[tex]\frac{AB}{XY}=\frac{BC}{YZ}[/tex]
Let the length of YZ be x.
Substituting the values, we get;
[tex]\frac{6}{12}=\frac{18}{x}[/tex]
Cross multiplying, we get;
[tex]6x=12 \times 18[/tex]
[tex]6x=216[/tex]
Dividing both sides by 6, we have;
[tex]x=36[/tex]
Thus, the value of x is 36.
Hence, the measure of the side YZ is 36 cm.