instructions in cp 4 are incomleate...how to to this exerise ????

# Math

**mtf**#2

The instructiions are pretty open-ended. We can try any math operations we like, for practice. For instance, we can do this...

```
r = 1
pi = Math::PI
v = (4/3.0) * pi * r**3
s = 4 * pi * r**2
c = 2 * pi * r
a = 2 * pi
print "Dimensional data for a sphere with unit radius:\n"
print "Volume = "
puts v
print "Surface = "
puts s
print "Circumferance = "
puts c
print "Arc length = "
puts a
```

Output

```
Dimensional data for a sphere with unit radius:
Volume = 4.1887902047863905
Surface = 12.566370614359172
Circumferance = 6.283185307179586
Arc length = 6.283185307179586
```