diff --git a/src/adapptlet.civet b/src/adapptlet.civet
index 65fe4ee..5b2840e 100644
--- a/src/adapptlet.civet
+++ b/src/adapptlet.civet
@@ -660,6 +660,13 @@ classHandler: Record<JoyceClass, ClassHandler> :=
             if args.scalar and args.scalar.length
                callbacks.push (api: AppletObject) =>
                   api.setCoords name, ...vertFlipped(args.scalar or [], cdata)
+         'meanProportional'
+            pt := args.subpoints
+            unless pt and pt.length is 6 then return
+            direction := `UnitVector(Vector(${pt[4]},${pt[5]}))`
+            lensq := `Distance(${pt[0]},${pt[1]})*Distance(${pt[2]},${pt[3]})`
+            disp := `sqrt(${lensq})*${direction}`
+            commands.push `${name} = Translate(${pt[4]},${disp})`
          'midpoint'
             if args.line
                commands.push `${name} = Midpoint(${args.line[0]})`
@@ -888,7 +895,7 @@ classHandler: Record<JoyceClass, ClassHandler> :=
                         moreParts[0].push newObj
                         api.setVisible newObj, false
          ///triangle|similar|parallelogram|application|quadrilateral
-               octagon|pentagon|hexagon///
+               |octagon|pentagon|hexagon///
             unless args.subpoints then return
             pt .= args.subpoints
             if method is 'parallelogram'