(a) The perimeter of the shape is the sum of half a circumference and the diameter itself.
The circumference of a circle with radius
is
, and since
we can write the circumference as

So, half a circumference is

Ad we get the perimeter by addind the diameter:

(b) Given the perimeter, we can solve for
:

So, we can divide both sides by the parenthesis and we have

1, 2, 4, 7, 14, 28
You can look at it as
1 x 28 = 28
2 x 14 = 28
4 x 7 = 28
hope this helps :)
7+8+9=24.. So 9 is the greatest..
Answer:
3.78 because u subtract 17.22 from 21