What is the scale factor of triangle abc to triangle def.
a: 2
b: 1/2
c: 1/6
d: 6

Little tip ** if u r going from a larger shape to a smaller shape, the scale factor is going to be a proper fractiona number less then 1 but greater then 0

BC = 66EF = 1166 times what is 11
66x = 11
x = 11/66 reduces to 1/6
so 66 * 1/6 = 11

now compare the other sides...
42 * 1/6 = 7looks like AC and DF
72 * 1/6 = 12...looks like Ab and DE

so ur multiplying every number in the big triangle by 1/6 , and getting the measures of the little triangleso ur scale factor is 1/6 <==