Learning to find the reference angle in the third quadrant

The video tutorial explains how to determine the reference angle for an angle of 205 degrees. It begins by defining the reference angle as the acute angle between the terminal side of an angle and the x-axis. The tutorial then demonstrates how to sketch 205 degrees in standard position, noting that it lies in the third quadrant. Finally, it calculates the reference angle by subtracting 180 degrees from 205 degrees, resulting in a reference angle of 25 degrees.

What is a reference angle?

• An angle that is always less than 45 degrees

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

• The angle formed by the Y-axis and the terminal side

• An angle that is always 90 degrees

In which direction do you rotate to sketch a positive angle?

• Clockwise

• Counterclockwise

• Horizontally

• Vertically

What is the standard position of an angle?

• When the angle is less than 90 degrees

• When the initial side is on the X-axis

• When the terminal side is on the X-axis

• When the initial side is on the Y-axis

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

• Add 90 degrees to the angle

• Subtract the angle from 360 degrees

• Add 180 degrees to the angle

• Subtract 180 degrees from the angle

What is the reference angle for 205 degrees?

• 35 degrees

• 15 degrees

• 25 degrees

• 45 degrees