Accepted Answer
[tex]A_1=\pi r^2\\\\R=2r\ then\ A_2=\pi R^2\to A_2=\pi(2r)^2=4\pi r^2\\\\A_2-A_1=4\pi r^2-\pi r^2=3\pi r^2=3A_1\\\\3=300\%\\\\Answer:(C).[/tex]
Suggested Answer
hope this helps in the picture below :)
Related Question in Mathematics
[tex]A_1=\pi r^2\\\\R=2r\ then\ A_2=\pi R^2\to A_2=\pi(2r)^2=4\pi r^2\\\\A_2-A_1=4\pi r^2-\pi r^2=3\pi r^2=3A_1\\\\3=300\%\\\\Answer:(C).[/tex]
hope this helps in the picture below :)