In the shortcut method, the area of the circle is obtained by multiplying the area of the bounding square by what factor?

• A. 0.5
• B. 1.0
• C. 0.785
• D. 1.25

Answer: (C)

When you use the shortcut method, the circle sits inside a bounding square with the circle’s diameter equal to the square’s side. If the square’s area is s^2, the circle’s area is pi (s/2)^2 = (pi/4) s^2. That means the circle’s area is pi/4 times the square’s area. Since pi/4 ≈ 0.785, multiplying the square’s area by 0.785 gives the circle’s area.