When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
After making their discoveries, they can check their answers using a key at the back of the book, where the prompted shapes are outlined in red. For example, on page 28, salt crystals with square sides may appear as diamonds when viewed from a corner.
When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.