<?xml version="1.0" encoding="utf-8"?>
<!-- Geometry Snacks #3 (What Fraction is Shaded?), drawn by hand as a ruler-and-compass construction.
     A rectangle ABCD on the hidden points A and B: perpendiculars to AB at A and B; the handle D slides along a hidden
     stretch of the perpendicular at A (from half the base to one and a half bases), starting where ABCD is a square, and
     C is where the parallel to AB through D meets the perpendicular at B. The left and top sides are quartered by
     midpoints of midpoints, every quarter point is joined to B, and the triangle on the second quarter of the left side
     is shaded: it is an eighth of the rectangle, whatever D makes the height. -->
<Drawing Version="1">
  <Viewport Left="-1.6" Top="6.6" Right="5.6" Bottom="-0.6" />
  <Scene Left="-1.6" Top="6.6" Right="5.6" Bottom="-0.6" />
  <Styles>
    <PointStyle Name="Handle" Size="15" Fill="#FFFFFFFF" Color="#FF1E1E1E" StrokeWidth="2.5">
      <Dark Fill="#FF1E2228" Color="#FFF2F2F2" />
    </PointStyle>
    <ShapeStyle Name="Red" Color="#FF000000" StrokeWidth="3" Fill="#FFEF303F">
      <Dark Color="#FFE8EBF0" Fill="#FFD9333F" />
    </ShapeStyle>
    <ShapeStyle Name="Frame" Color="#FF000000" StrokeWidth="3" IsFilled="false">
      <Dark Color="#FFE8EBF0" />
    </ShapeStyle>
    <LineStyle Name="Ink" Color="#FF000000" StrokeWidth="3">
      <Dark Color="#FFE8EBF0" />
    </LineStyle>
  </Styles>
  <Figures>
    <FreePoint Name="A" Visible="false" Locked="true" X="0" Y="0" />
    <FreePoint Name="B" Visible="false" Locked="true" X="4" Y="0" />
    <Segment Name="AB" Visible="false">
      <Dependency Name="A" />
      <Dependency Name="B" />
    </Segment>
    <PerpendicularLine Name="a" Visible="false">
      <Dependency Name="AB" />
      <Dependency Name="A" />
    </PerpendicularLine>
    <PerpendicularLine Name="b" Visible="false">
      <Dependency Name="AB" />
      <Dependency Name="B" />
    </PerpendicularLine>
    <!-- the stretch of the perpendicular at A the handle slides on: half a base up to one and a half, by circles about A -->
    <MidPoint Name="H" Visible="false">
      <Dependency Name="A" />
      <Dependency Name="B" />
    </MidPoint>
    <Circle Name="half" Visible="false">
      <Dependency Name="A" />
      <Dependency Name="H" />
    </Circle>
    <IntersectionPoint Name="Lo" Visible="false" Algorithm="IntersectLineAndEllipse1">
      <Dependency Name="a" />
      <Dependency Name="half" />
    </IntersectionPoint>
    <ReflectedPoint Name="B2" Visible="false">
      <Dependency Name="A" />
      <Dependency Name="B" />
    </ReflectedPoint>
    <MidPoint Name="H3" Visible="false">
      <Dependency Name="B" />
      <Dependency Name="B2" />
    </MidPoint>
    <Circle Name="threeHalves" Visible="false">
      <Dependency Name="A" />
      <Dependency Name="H3" />
    </Circle>
    <IntersectionPoint Name="Hi" Visible="false" Algorithm="IntersectLineAndEllipse1">
      <Dependency Name="a" />
      <Dependency Name="threeHalves" />
    </IntersectionPoint>
    <Segment Name="Slide" Visible="false">
      <Dependency Name="Lo" />
      <Dependency Name="Hi" />
    </Segment>
    <PointOnFigure Name="D" Style="Handle" X="0" Y="4" Parameter="0.5">
      <Dependency Name="Slide" />
    </PointOnFigure>
    <ParallelLine Name="d" Visible="false">
      <Dependency Name="AB" />
      <Dependency Name="D" />
    </ParallelLine>
    <IntersectionPoint Name="C" Visible="false" Algorithm="IntersectLineAndLine">
      <Dependency Name="d" />
      <Dependency Name="b" />
    </IntersectionPoint>
    <!-- quarter points of the left side AD and of the top side DC -->
    <MidPoint Name="M1" Visible="false">
      <Dependency Name="A" />
      <Dependency Name="D" />
    </MidPoint>
    <MidPoint Name="M0" Visible="false">
      <Dependency Name="A" />
      <Dependency Name="M1" />
    </MidPoint>
    <MidPoint Name="M2" Visible="false">
      <Dependency Name="M1" />
      <Dependency Name="D" />
    </MidPoint>
    <MidPoint Name="N1" Visible="false">
      <Dependency Name="D" />
      <Dependency Name="C" />
    </MidPoint>
    <MidPoint Name="N0" Visible="false">
      <Dependency Name="D" />
      <Dependency Name="N1" />
    </MidPoint>
    <MidPoint Name="N2" Visible="false">
      <Dependency Name="N1" />
      <Dependency Name="C" />
    </MidPoint>
    <Polygon Name="ABCD" Style="Frame">
      <Dependency Name="A" />
      <Dependency Name="B" />
      <Dependency Name="C" />
      <Dependency Name="D" />
    </Polygon>
    <Segment Name="M0B" Style="Ink">
      <Dependency Name="M0" />
      <Dependency Name="B" />
    </Segment>
    <Segment Name="M1B" Style="Ink">
      <Dependency Name="M1" />
      <Dependency Name="B" />
    </Segment>
    <Segment Name="M2B" Style="Ink">
      <Dependency Name="M2" />
      <Dependency Name="B" />
    </Segment>
    <Segment Name="DB" Style="Ink">
      <Dependency Name="D" />
      <Dependency Name="B" />
    </Segment>
    <Segment Name="N0B" Style="Ink">
      <Dependency Name="N0" />
      <Dependency Name="B" />
    </Segment>
    <Segment Name="N1B" Style="Ink">
      <Dependency Name="N1" />
      <Dependency Name="B" />
    </Segment>
    <Segment Name="N2B" Style="Ink">
      <Dependency Name="N2" />
      <Dependency Name="B" />
    </Segment>
    <Polygon Name="Shaded" Style="Red">
      <Dependency Name="B" />
      <Dependency Name="M0" />
      <Dependency Name="M1" />
    </Polygon>
  </Figures>
</Drawing>
