Circle Folding

 1. Cut out circle  2. Fold the circle in half  3. Fold the circle in fourths  4. Unfold and mark the center with a dot  5. Write your name on the opposite side in the center of the circle.

 Draw a line on a fold that goes through the center. What is this line called?  Draw a line on a fold that starts at the center and goes to the outside edge of the circle. What is this line called?

 Take the edge of the circle and fold it to the center. Draw a line on this fold. What is the name of this line?  Fold another edge to the center so that the resulting shape looks like an ice cream cone.  Fold down the remaining edge to the center.  What shape have you made? What is true about this shape? Prove it without using a ruler.

 Fold one vertex of the triangle down so that it touches the center of the opposite side. What shape have you created?  Fold one of the acute vertices of the trapezoid over so that it meets one of the obtuse vertices. What shape have you made?  Fold one of the acute vertices of the rhombus so that it touches the other acute vertex.

 Student A’s unfold your shape back to the original triangle. Student B’s leave your triangle folded. Compare the two shapes you have. What is the ratio of the length of a side of the large triangle to the length of the side of the small triangle? Prove it without a ruler.

 All student’s unfold shapes back to original large triangle.  Fold the three vertices of that triangle in so that each is touching the center point.  What shape did you make? Is it regular?  Unfold to the original triangle, refold to make a triangular pyramid.

 Fold the top halves of the triangles down across each other to make a truncated triangular pyramid.  Decorate the sides of this “jewelry box”.  Each figure must have a Geometry concept represented on it  -see the rubric for how you will be graded  We will put 20 of these jewelry boxes together to make a dodecahedron.

Tape together 4 triangles like this (on the back side)

Tape the 5 strips together down the center strip on the back side.

 From the inside of the ball, piece triangles together  You may have to remove the last triangle in order to get the final pieces taped  (the last one is the hardest!)