Circle Folding 1 Cut out circle 2 Fold
- Slides: 11
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!) ¡
