[CD] Write a program that reads in the radius of a circle and prints the circle’s diameter, cir- cumference and area. Use the constant value 3.14159 for ?. Do these calculations in output state- ments.

What will be an ideal response?

```
# Given the radius of a circle, output its diameter,
# circumference and area.

# obtain user-entered radius
radius = raw_input( "Enter the circle's radius: " )
radius = float( radius )

pi = 3.14159 # use 3.14159 for pi

# calculate and print the circle's diameter
print "Diameter is", ( 2 * radius )

# calculate and print the circle's circumference
print "Circumference is", ( 2 * pi * radius )

# calculate and print the circle's area
print "Area is", ( pi * radius ** 2 )
```
Enter the circle's radius: 8
Diameter is 16.0
Circumference is 50.26544
Area is 201.06176