The area of a circle is approximately 3.14 times the radius squared. Which of the following expressions is a correct way to write this, if the radius is 3x?

Question

The area of a circle is approximately 3.14 times the radius squared.  Which of the following expressions is a correct way to write this, if the radius is 3x?

johnweldon1993 · Answer

The area (lets say 'A' is = to 3.14 times the radius squared ...so

$$A = 3.14 r^2$$

If the radius is 3x we have

$$A = 3.14 (3x)^2$$

Which would then simplify to

$$A = 3.14 \times 9x^2$$

anonymous · Answer

These are the answers 
		
3.14(3x)2
		
(3x)(3.14)2
		
3.14(3)x2
		
9(3.14)x

That i get to choose from

johnweldon1993 · Answer

So then it's the one I wrote BEFORE that simplification...

3.14(3x)^2

So A in your case