Ready-made PDF here: http://test.geogebra.org/~mike/Sliceform9cm.pdf[br]Works best on two colors of card (two shades of green for a Christmas Tree)[br][br]Finished version should look like this:[br]https://www.pinterest.com/pin/517632550894188865/[br][br]Here's an alternative pop-up version![br]http://www.craftster.org/forum/index.php?topic=282491.0[br][br]Reference: look for books on Sliceforms by John Sharp from your favorite bookshop