What plant is shaped like a hemisphere on a round stem?
Do you see how to draw a row of these shapes, or a border of semicircles?
These pictures show you how to get a square and an oblong from a square prism.
Draw an oblong four inches long and two inches wide. Draw a three-inch square.
Draw an oblong table-cloth with a border of squares in a row.
Lay a row of tablets: first, an oblong; then a square. Draw this border on a paper towel.
One of the drawings on this page is called a right triangle. Can you find it?
Think how you can get a right triangle from a right tri-prism.