reference angle to pi/10: solve sin inverse sin(-pi/10)

[NXT25]

How would you find the reference angle to pi/10. how would you solve sin inverse[sin(-pi/10)]?

 

[Aladdin]

How would you find the reference angle to pi/10.

The "reference angle" is the acute angle between the terminal side of the given angle and the x-axis
Convert the radians to degrees.
Draw the angle.
1. If angle A is in quadrant I then the reference angle
A r = A.