C=

so
18.84=2*3.14r
18.84=6.28r
r=3

A=3.14*9
A=28.26 or when rounded is 28
Hope that helps
X=20,-16 but i don't sure
Answer:
x > -24
Step-by-step explanation:
18 - 3x < 90
Subtract 18 from both sides.
-3x < 72
Divide both sides by -3. (When diving by a negative, flip the sign.)
x > -24