- Draw a table with three columns. Write the angles 0, 30, 45, 60, and 90 (in degrees) on the first column.
- Write the integers 0 to 4 in order on the second column, and 4 to 0 on the third column.
- Take the square roots of all entries of the second and third columns.
- Divide all answers by 2. You should now have the sine and cosine function values of the given angles.
Does this have any geometric interpretation or significance? I don't think this is a coincidence, because virtually everything is related in mathematics.