10a ) Which of the following is not a characteristic of both surveys and observational studies? A.
The researcher does not control or change the population.
B.
The researcher exercises direct control over at least one variable.
C.
Data are collected about a population.
D.
Results are not used to prove cause and effect.

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6

care to share were the trapezoid shown is ?

i'm not really sure how to answer that

step-by-step explanation: