Answer:
[tex]17.3\:\mathrm{m}[/tex]
Step-by-step explanation:
The circumference of a circle is given by [tex]C=2r\pi[/tex], where [tex]r[/tex] is the radius of the circle.
By definition, the radius is equal to half the diameter. Therefore, a circle with a diameter of 5.5 meters has a radius of [tex]5.5\cdot \frac{1}{2}=2.75[/tex] meters.
Thus, the circumference of the silo must be:
[tex]C=2\cdot 2.75\cdot \pi=17.2787595947\approx \boxed{17.3\:\mathrm{m}}[/tex](rounded to one decimal place as requested by question).
*Units for circumference should be in the same units as the radius/diameter is given in, since the circumference just refers to the perimeter of a circle.
**Your work for question 2 should include an equals sign, not an addition sign, between the part where you're adding the sevens and multiplying them: [tex]\implies 7+7+7+7+7+7\boxed{=}7\cdot 6[/tex]
