The area scales with the square of the scale factor: the dilation has a certain scale [tex]k[/tex], the area scales with a factor [tex]k^2[/tex].
So, if ABC is scaled by 5 to for A'B'C', the area of A'B'C' will be [tex]5^2=25[/tex] times the area of ABC.
The other exercise is basically identical.
