    #! /usr/local/bin/ruby -w
    require 'RMagick'

    i = Magick::ImageList.new
    i.new_image(300, 220, Magick::HatchFill.new("seashell"))

    gc = Magick::Draw.new

    # Draw the arc
    gc.fill_opacity(0)
    gc.stroke('red').stroke_width(3)
    gc.arc(130,30, 200,100, 45,90)

    # Draw circles around the endpoints
    gc.stroke_width(1)
    gc.stroke('gray50')
    gc.circle(130,30, 133,33)
    gc.circle(200,100,203,103)

    # Annotate
    gc.fill_opacity(1)
    gc.fill('black')
    gc.stroke('transparent')
    gc.text(137,30, "'130,30'")
    gc.text(207,100, "'200,100'")
    gc.draw(i)
    i.write("arc.gif")