This section is from the book "Manual Of Cardboard Construction For Third And Fourth Grades", by Charles A. Kunou. Also available from Amazon: Manual of cardboard construction for third and fourth grades.
Draw base line 3½" long.
With compasses draw arcs 1 and 2, - 4¼" radius.
Draw sides of triangle.
Measure 1" from base line and draw line XX and place points 3 and 4, - ½" from sides of triangle. Measure ½" on base line and connect these points with points 3 and 4. Draw lines 3, 5 and 4, 6,-½" long using triangle, then connect points 5 and 6. Cut out figure with scissors. Roll flap A forward and upward, making a "rest" to hold picture on as in sketch. For back supporter, draw and cut a piece of tagboard 3½'x½" and fasten the same with paper fasteners 1" from apex, as shown in drawing. Material: Tagboard.


 
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