Hey arb123.
What do you mean for the inner circle? I only see one circle in your diagram and you have the area of that circle in your post.
I know that you have to do
area of circle-area of inner square
Area of outer square
the area of the circle= (3.1413)r^2
the area of outer square= 4r^2
But i cant figure out the area of the inner circle?
can anyone help me?
Hi arb123.
Notice that if you split the inner square into two triangles, you will have two triangles with base 2r and height r.
We have:
A circle with area:
A square with area:
A larger square with area:
The shaded area is thus:
The probability of the dart hitting the shaded area and NOT the white area inside the larger square, between its corners and the circle is thus:
Does this image help you understand why the height is r and the base is 2r? http://s9.postimage.org/5zb7sblnj/expl.png