Implement 'angle' and 'magnitude' in scheme

[Katie Burke]

angle should return the angle part of the polar representation of num.
magnitude should return the magnitude of num.
( http://www.scheme.com/tspl4/objects.html#./objects:s124 )

This should return 0.0

(angle 5.2)

Traceback (most recent call last):
File "stdin", line 1, col 2
RunTimeError: unbound variable 'angle'

This should return 1

(magnitude 1)

Traceback (most recent call last):
File "stdin", line 1, col 2
RunTimeError: unbound variable 'magnitude'

[Katie Burke]

I'm not sure if this is a separate issue, but when I input this:

(angle 7.3@1.5708)

I should get 1.5708.
And without angle implemented, I expected to get an 'unbound variable' error, but instead, I get this...
Traceback (most recent call last):
File "stdin", line 1, col 8
RunTimeError: unbound module '7'