** 17) If A is the area of circle, which of the following is an expression for A in terms of C?**

(A) C^{2}/4π

(B) C^{2}/4π^{2}

(C) 2C

(D) 2C^{2}π

** 18) What is the area of a circle whose radius is the diagonal of a square whose area is 4?**

(A) 2π

(B) 2π√2

(C) 4π

(D) 8π