Geometric Model by A. Harry Wheeler, Two Angles and Two Planes
To show relationships among planes and angles, A. H. Wheeler designed a series of what he called platform models. All of these had a rectangular platform, with other segments (often other rectangles) secured to it. This tan paper platform model shows two parallel planes cut by two planes that are at an angle to one another.
A paper tag on the model reads: 2A-2PL*.
For the pattern, see 1979.3002.109. The pattern is dated March 11, 1945, hence the rough date assigned to the model.