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A better way to define angles is to use a unit of angular measure called the radian.
A radian is a better method because it uses the circle itself to define angular
measure rather than some historical arbitrary division like degrees.

Figure 41-8 A radian is the angle when inserting the radius into the circumference

A radian is how many times the radius of a circle will fit into its circumference. We
know the circumference of a circle is C=2πr where r is the radius. So, there are 2π
radiuses (or radii) in the circumference of a circle. You cannot fit an even number of
radiuses into the circumference of a circle. There are 2π or roughly 6.2831853'
radiuses in a circle- each radius is called a radian. 2π is called "Tau" after the Greek
letter that looks like a small "t". This is not used much but some argue it would be
easier if we did.

So, 2π radian is 360°, then π radians (or rads) is 180°.

Let’s convert 30° to radians.

radians (rads) = degrees x π/180 so 30° is 30xπ/180 = 0.523598775 radians or rads.

To be clear, we are starting from sin(30°) or sin(0.523598775 rads).

We are now going to use the Taylor series to find the sine of the angle 30° or
0.523598775 radians.

Let B = 0.523598775 rads (store in Memory/Variable B)

sin(B)= B-(B3/3!)+(B5/5!)-(B7/7!)..,

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