Bunuel wrote:

On a map, 1 centimeter represents 4 kilometers. A circle on the map with a circumference of 3π centimeters represents a circular region of what area?

(A) 6π km^2

(B) 12π km^2

(C) 36π km^2

(D) 72π km^2

(E) 144π km^2

Answer C

Circumference, 2πr, of circle on the map, means radius equals:

\(2πr = 3π\) cm

\(r = \frac{3}{2}\) cm

Actual radius of the circular region?

\(\frac{Scale}{Actual} = \frac{1cm}{4km}=\frac{(\frac{3}{2}cm)}{Xkm}\)

\(x = (4) * (\frac{3}{2}cm) = 6 km\)

That is, r = \(\frac{3}{2}\) cm on the map = actual length of r = \(6\) km

Actual area of circular region in km, where actual \(r = 6\) km:

\(πr^2 = (6 km)^2* π = 36π km^2\)

Answer C

_________________

In the depths of winter, I finally learned

that within me there lay an invincible summer.

-- Albert Camus, "Return to Tipasa"