Pi and Diameter of Circle

Ahmed measured the diameter (d) and circumference (C) of a circle accurately to the nearest mm, with the results:

d = 113 mm

C = 355 mm

He then used his measurements to calculate a value for π correct to 7 decimal places. What value did he get?

• 3.1415926

• 3.1415927

• 3.1415928

• 3.1415929

To mathematically calculate the special number "pi" you need the __________________________.  

• circumference  &  the diameter 

• diameter  &  the radius 

• any two parts of the circle 

What is the best way to find pi?

• 3.1415...

• 22/7

• C/D

• 20 x 3.1415...

Which is just an estimate or approximation of pi?

• 22/7

• pi

• C/D

• 3

Determine the radius of the penny

• 59.66 mm

• 9.5 mm

• 38 mm

• 119.32 mm

If the radius of a circle is 12.5 meters, the diameter is ____

• 6.25 meters

• 125 meters

• 25 meters

• 50 meters

If the diameter of a circle is 50 yards, the radius is _____

• 100 yards

• 25 yards

• 150 yards

• 15 yards

One diameter will not wrap around a circle, but approximately  _____________ diameters will wrap around the outside of the circle. 

• three

• two 

• 100