Question

the largest of these five squares has side length 27 units, and each additional square's side length is 2/3 as large as the one before. What is the perimeter and area of the entire shape?

Answer 1

PERIMETER: 584/3, AREA: 11605/9

Explanation:

PERIMETER: The side lengths form a geometric series with a = 27, and r = 2/3. Along the bottom we see all five lengths, and those same lengths are seen along the top. The sum of these lengths is 27+18+12+8+16/3=211/3.

We can also calculate this as the sum of the geometric series:

27 (1 - (2 / 3) ^ 5)/ 1 - (2 / 3) = 27(1 - 32 / 243)/ (1 / 3) = 81 x 211/243 = 211/3

We see these lengths twice, once along the bottom and once as horizontal segments on the top. We also add the left side of 27. The vertical segments on the right must also have a total length of 27, since they cover the same ground as the left side.

The total perimeter: 2 x 211/3 + 2 x 27 = 584/3

AREA: 27^2 + 18^2 + 12^2 + 8^2 + (16/3)^2 = 11605/9