Question

If π is rounded to a whole number, what is a reasonable estimate for the circumference of a circle with a diameter of 9 cm? 27 cm 28 cm 30 cm 36 cm

Answer 1

The estimate would be about 28 cm

Answer 2

Circumference of circle= 2*pi*r

You need to figure out the radius from the diameter. The radius is half of the diameter. Therefore, the radius in this problem is 4.5.

Since you are rounding pi to a whole number, 3.14 would be converted to 3. 

This is now the equation: 2*3*4.5

27 cm