I'm assuming a quarter-circle is exactly 1/4 of a circle. Thus if you have 4 congruent quarter-circles, that should mean they make a complete circle.
If that is the case, then we can find the area of the full circle using pi*r^2.
So the area of the circle is 5^2*pi or 25pi.
To find the area of the shaded region, we subtract the area of the circle from the area of the square.
The area of the square is 10^2 or 100.
So the area of the shaded region is 100 - 25pi.
My calculator says that equals roughly 21.46
Answer: The answer is Yes.
Step-by-step explanation: Given in the question that Radric was asked to define "parallel lines" and he said that parallel lines are lines in a plane that do not have any points in common. We are to decide whether Radric's definition is valid or not.
Parallel lines are defined as lines in a plane which never meets or any two lines in a plane which do not intersect each other at any point are called parallel.
Thus, Radric's definition is valid.
Answer: Choice D 
Reason:
Exponential functions have the variable in the exponent.
Choice A is a polynomial, which means we can rule it out. Choice B is a log function, so we can rule it out also.
Choice C is a rational function because it is a ratio of two polynomials. This rules out choice C.
Choice D is the only function with the variable in the exponent. That is assuming you meant to say instead of 
The number is = 10x+y
if reverse the digits, the number is: 10y+x
The sum fo its digits is = x+y=5
I suggest this system of equations:
(10y+x)-(10x+y)=27 ⇒9y-9x=27
x+y=5
We can solve this system of equations by equaliztion method
x=5-y
9y-9(5-y)=27
9y-45+9y=27
18y=27+45
18y=72
y=72/18
y=4
x=5-y
x=5-4=1
The number is: 10x+y=10(1)+4=14
Answer: the number is 14
