To find the surface area of a spherical object, we need to know the radius of the sphere. However, in this case, only the circumference of the pincushion is given, which is not enough information to directly determine the radius.
The formula relating the circumference (c) and the radius (r) of a sphere is:
c = 2πr
To find the surface area (A) of the sphere, we can use the formula:
A = 4πr^2
Since we don't have the radius, we need to solve the circumference formula for the radius first:
c = 2πr
Divide both sides of the equation by 2π:
r = c / (2π)
Now we can substitute the value of c = 18 cm into the equation to find the radius:
r = 18 cm / (2π)
r ≈ 2.868 cm (approximately)
Now that we have the radius, we can calculate the surface area using the formula:
A = 4πr^2
A = 4π(2.868 cm)^2
A ≈ 103.05 cm² (approximately)
Therefore, the surface area of the pincushion is approximately 103.05 square centimeters.