Are these 2 different questions or is this one equation
The answer would be the first choice. 
Explanation: The reason for this is that the question was pretty much just asking what the area of the resulting two-dimensional cross section would be -the shape in gray- (which can be found by using the formula
. To add on, since the dimensions of the shape are already given (5 and 3) all you've to do is multiply: 3*5=15
That's how you get to the answer.
First split your model into 10 equal sections then you shade/color in 6 of them.
There it goes that is 6/10 bench mark!
~JZ
Hope it helps
Answer:
Well, in reality, all circles are similar to each other. They will all have the same angles, and they don't really have side lengths. So, they are similar.
But to PROVE they are similar, we will transform Circle C to match circle E.
Circle C has a center at (-3, 1), and Circle E has a center of (4, 9). For Circle C to have the same center as Circle E, we will translate Circle C 7 units to the right, and 8 units up.
Since Circle C has a radius of 4, and Circle E has a radius of 3, dilate Circle C by a factor of 3/4. That way, the radius is 3 units as well.
And there you go! The two circles will map perfectly on top of each other.
Hope this helps!