Of the following options, which is most helpful in developing the effective study habit of staying organized? Keep pens, pencils, and highlighters off the desk. Put all computer files in one folder on the desktop. Store notes for all courses in a single notebook. Use a calendar to keep track of assignment due dates.

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

the answer to your question is c.)   volcanoes built the mountains and earthquakes tore them down.

step-by-step explanation: