Can you please help me

6 cm, because the second shape is 2/3 of the first shape, which makes the 15 got to 10, as well as the 9 go to 6 cm which is your answer

The question is kind of confusing. if it's asking how many variations of answers can you give. then do 4^5 for your answer.this would be something like the first question could be a and the 2nd c or first b next c etc. if you can, ask the teacher for a better confirmation of what it's asking. if i'm assuming correctly what it's asking, it's 625 different variations.