C=2pir
r=4
c=2pi4
c=8pi
aprox pi=3.14
c=25.12
Estimation would give you an answer close to the actual answer so you can see if your answer is reasonable depending on how close the estimate is
Hardest thing like an object is metal.
Hardest thing like something someone struggles with is geometry.
Answer: 40 PLEASE MARK BRAINLEST
Step-by-step explanation:
The answer is C because 51×-2=-102 and 51×-0.5=-25.5
So it -102+(-25.5) or C