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## Geometric Intersections (#233)

HIRB

This week's quiz is to detect the intersections of various geometric
elements: circles, lines, and polygons.

A circle is defined by a point and a radius.

point = [6, 3]
radius = 5
a = Circle.new(point, radius)

A line can be defined by two points, or a point and a slope.

p1 = [0, 0]
p2 = [4, 2]
line = Line.new(p1, p2)
slope = 0.5
line = Line.new(p1, slope)

A polygon can be defined as a collection of points.

b1 = [2, 9]
b2 = [1, 3]
b3 = [7, 5]

b = Polygon.new(b1, b2, b3)

def intersect(a, b)
  # Should return true or false indicating whether or not
  # a and b intersect. a and b can be any circle, line or
  # polygon.
end

You may also find it more natural to define a.intersect(b) or
b.intersect(a). The relation should be symmetric and reflexive, though
not transitive.

Which methods you choose to add to the geometric elements is up to
you, the only hard requirement is that the intersect method(s) return
the correct truth values.

Have fun!

Extra Credit: handle the "edge" cases of the polygon comprised of one
point (a single point) or two points (a line segment).

Extra Extra Credit: Provide a graphical and colorful output indicating
intersections.

-- 
-Daniel
http://rubyquiz.strd6.com