Welcome to Westonci.ca, the place where your questions are answered by a community of knowledgeable contributors. Explore comprehensive solutions to your questions from knowledgeable professionals across various fields on our platform. Explore comprehensive solutions to your questions from knowledgeable professionals across various fields on our platform.

If the radius of a circle is increased by 100%, then the area is increased by:
(A)100% (B) 200% (C) 300% (D) 400% (E) none of these


Sagot :

[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 :)