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Sine and Cosine for Connected Angles

The length AM can be calculated using trigonometry in two different ways. Create this pair of equivalent calculations for different peg boards, notice a general result, and account for it.

Round and Round a Circle

Stage: 4 Challenge Level: Challenge Level:1

Watch the animation.
Can you explain what is happening?
What do you notice about the numbers that appear towards the end of the sequence?
Can you explain how they vary and why?
What would happen if the dot kept going around the circle increasing the angle beyond 360 degrees?

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After this you might like to look at the problem Trigonometric Protractor.