Need help with 1-4.

Answer:
for number 4 the answer is 32 in (please read below)
Step-by-step explanation:
I will do one of them for now... how about number 4.
Similar triangles means we are going to setup a proportion:
Small triangle Big Triangle
Corresponding 12 15
Corresponding x 40
So the proportion is 12/x=15/40
cross multiply
12(40)=15(x)
Divide both sides by 15
giving x=12(40)/15=32
Try number 1... And I will check it for you (just post as a new question-I will be looking for it)
Answer:
1. 8 cm
2. 15 cm
3. 28 cm
4. 32 cm
Step-by-step explanation:
1. 12/6= 2
20/10= 2
Scale Factor= 2
16/2= 8cm
2. 30/18= 1.6666667
15/9= 1.6666667
Scale Factor= 1.6666667
25/1.6666667= 15cm
3. 16/12= 1.333333
32/24= 1.333333
Scale Factor= 1.333333
(21)(1.333333)= 28cm
4. 15/12= 1.25
25/20= 1.25
Scale Factor= 1.25
40/1.25= 32cm