How to determine the reference angle of an angle in degrees

The video tutorial explains reference angles, which are acute positive angles between the X-axis and the terminal side. It emphasizes the importance of understanding reference angles without needing to sketch them. The tutorial uses a 125-degree angle as an example, showing how to calculate the reference angle by subtracting from 180 degrees, resulting in a 55-degree reference angle. The video also clarifies that reference angles are always positive, regardless of direction.

What is a reference angle?

• An angle that is always negative

• An angle that is always greater than 180 degrees

• The angle between the Y-axis and the terminal side

• The acute positive angle between the X-axis and the terminal side

If an angle is 125 degrees, what is the reference angle?

• 55 degrees

• 125 degrees

• 180 degrees

• 90 degrees

Why are reference angles always positive?

• Because they are measured counterclockwise

• Because they are measured clockwise

• Because they are always less than 90 degrees

• Because direction does not matter for reference angles

What does Theta prime represent?

• The angle between the Y-axis and the terminal side

• The reference angle

• The original angle

• The angle of rotation

How do you calculate the reference angle for an angle in the second quadrant?

• Subtract the angle from 360 degrees

• Add 90 degrees to the angle

• Subtract the angle from 90 degrees

• Subtract the angle from 180 degrees