By definition, the circumference of a circle is:
[tex]c = 2 * pi * r
[/tex]
The area of a circle is:
[tex]a = pi * r ^ 2
[/tex]
Where,
r: radius of the circle.
When the radius is double, then the new area is:
[tex]A = \pi*(2r)^2
[/tex]
Rewriting we have:
[tex]A = 4 * \pi * r ^ 2
[/tex]
In terms of a we have:
[tex]A = 4 * a[/tex]
Answer:
The new area of the circle in terms of a is:
[tex]A = 4 * a[/tex]
