Answer:
Options A-C-F
Step-by-step explanation:
we know that
<em>The circumference of a circle is equal to</em>
or 
where
D is the diameter and r is the radius
therefore
or 
The number pi is the ratio circumference - diameter or is the ratio circumference - 2 times radius
<em>The area of the circle is equal to</em>

therefore
The number pi is the ratio Area - radius squared
Answer:

Step-by-step explanation:
Answer: 9
Step-by-step explanation:
s = 7
k = 4
x = 6
7 - 4 + 6
3 + 6
9