Question

I don't know whats wrong, please help. It is the exact formula.

Answer 1

The formula for circumference is 2$\pi$r, where r is equal to radius.
It states to use 3.142 for pi
It also provides you with the diameter, not the radius, so you have to divide it by two to get 4.5
2*3.142*4.5= approximately 28.278 or 28.3

Answer 2

The equation for circumference is: 2 x Pi x r

You used the diameter (9), rather than the radius. The radius is the diameter divided by 2. Therefore, your equation should be: 2 x 3.142 x 4.5, NOT 2 x 3.142 x 9.

This means your answer should be 28.3. Hope this helps! Just a minor mistake (: