SHADOW GEOMETRY

Trivett carries the series' activity-oriented policy to extremes here. The only concepts, terms or generalizations introduced as such are peripheral ones toward the end, where it is noted that ""the shaggy surface of the grass DISTORTS the shadow"" of a tree and that ""different surfaces"" -- your face, your stomach, or a beach ball -- also distort shadows. To get that far readers (""you"" and ""your friend"") have to go through the motions -- with no suggestion as to why they should bother or what it all means -- of tracing each other's shadows on the pavement in different positions, making ""monster shadows,"" watching their shadows as their bodies or the light source move, and -- here comes the geometry -- cutting triangles and other unspecified shapes out of paper in order to experiment with their shadows. For teachers perhaps, the shade of a lesson plan.