So I'm doing this portfolio item for math and I just really really need help with the explain it part!

Use your design and analysis to write a website posting describing the process
readers can use to make a string of pennant flags using any length string and any
size square. Your posting should include the following:
 step-by-step instructions
 a formula that can be used to find the diagonal length of any paper square
and a formula that can be used to find the total number of triangles needed
 diagrams that make the instructions and formulas easier to understand
 an explanation of why this craft project must involve estimation and your
recommended level of precision that readers should use