This circle is centered at the origin, and the length of its radius is 4. What is the circle's equation?
5+
4
-5
5
-5-
A. x2 + y2 =16
B. x + y = 4
C. X6 + y = 4
D. x2 + y2 = 4

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm