"""
------------------------------------------------------------------------------
--                                                                          --
--                      FEBRUARY 21 LECTURE EXAMPLES                        --
--                                                                          --
--                           F E B 2 1 . P Y                                --
--                                                                          --
------------------------------------------------------------------------------
-- Jeremy D Keffer                                                          --
--                                                                          --
-- CISC106 011 Spring 2013                                                  --
--                                                                          --
------------------------------------------------------------------------------
-- This file contains all the code we wrote in class on Feb 21.             --
--                                                                          --
------------------------------------------------------------------------------
"""

import math

def rectangle_area(length, width):
    """
    Computes the area of rectangle with length 'length' and width 'width'.
    """
    area = length * width
    return area


def distance(x1, y1, x2, y2):
    """
    Calculates the distance between points (x1, y1) and (x2, y2) on a 2d plane.
    """
    return math.sqrt((y2 - y1)**2 + (x2 - x1)**2)

def circle_area(radius):
    """
    What did we forget to do here?
    """
    return math.pi * radius**2

def divisible(number, factor):
    """
    Returns whether or not number is evenly divisible by factor (i.e. the
    quotient is a whole number)
    """
    return number % factor == 0