Answer: Yes, Yukio is correct.
Step-by-step explanation:
Assuming that Triangle DEF and ABC have the same angles (they do because they are right-angled), we can take the length from the larger triangle (DEF) and divide it by the length of the smaller triangle (ABC).
Length of DEF = 6cm
Length of ABC = 2cm
= 6/2
= 3
Proves that scale of DEF to ABC is 3:1
