Use a Ferris wheel to soar to new heights of understanding on double angle identities. Here is an interactive that applies an example of a Ferris wheel to show how doubling the angle does not double the value of a trigonometric ratio....

Knowing the addition formulas allows for the calculations of double and half formulas. The fourth installment of 16 has the class use the addition formula to develop the double angle trigonometric formulas. Using the double formula,...