Understanding Reference Angles

The video tutorial explains how to find reference angles for both positive and negative angles, including those in radians. It covers the concept of reference angles, how they relate to the x-axis, and provides formulas for finding them in different quadrants. The tutorial also includes examples and explains how to handle negative angles by finding coterminal angles. Additionally, it discusses reference angles for common angles in the unit circle and provides methods for converting between degrees and radians.

What is the reference angle for an angle of 120 degrees?

• 120 degrees

• 90 degrees

• 60 degrees

• 30 degrees

What is the reference angle for an angle of 210 degrees?

• 120 degrees

• 90 degrees

• 60 degrees

• 30 degrees

Which formula is used to find the reference angle for an angle in quadrant two?

• 180 minus the angle in quadrant two

• Angle in quadrant two

• Angle in quadrant two minus 180

• 360 minus the angle in quadrant two

What is the reference angle for an angle of 315 degrees?

• 90 degrees

• 45 degrees

• 30 degrees

• 60 degrees

How do you find the reference angle for a negative angle like -150 degrees?

• Multiply the angle by -1

• Divide the angle by 2

• Subtract 360 from the angle

• Add 360 to the angle

What is the reference angle for a negative angle like -240 degrees?

• 60 degrees

• 120 degrees

• 30 degrees

• 90 degrees

What is the reference angle for 2π/3 in radians?

• π/2

• π/6

• π/4

• π/3

Which of the following angles share the same reference angle of π/4?

• 7π/6

• 11π/6

• 2π/3

• 5π/4

How can you find the reference angle for a non-common angle like 3π/5?

• Convert to degrees and back to radians

• Use a calculator

• Estimate visually

• Use the unit circle

What is the reference angle for an angle of 9π/8?

• π/4

• π/8

• π/6

• π/3