The equation of the circle whose center is at (2, 1) and radius is 3 is (x + 2)² + (y + 1)² = 9 (x - 2)² + (y - 1)² = 9 (x - 2)² + (y - 1)² = 3

  (x - 2)² + (y - 1)² = 9

Step-by-step explanation:

The standard form equation of a circle with center (h, k) and radius r is ...

  (x -h)² +(y -k)² = r²

Filling in (h, k) = (2, 1) and r = 3, you have ...

  (x -2)² +(y -1)² = 9

12*c

step-by-step explanation:

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