Terminal Angles Unit Circle

Mathematical Equivalence

ON

The Unit Circle has four quadrants such that:

• All quadrants have 90 degrees

• Quadrant IV is between π and 3π/2 radians

• Quadrant III is between 3π/2 and 2π and radians

• Quadrant I is where the acute angles are

• undefined

Answer explanation

Using θ as a reference angle, mark the triangle sides as Opp, Adj, and Hyp. Label these on the triangle on your paper.

• Opp

• OP

• Hyp

• y

• Adj

• x

You start on the unit circle at (0, -1) and move 300° counterclockwise. Which angle (in degrees) will you end up on the unit circle?

• 30

• 330

• 210

• 120

Which of the following angles are co-terminal to 330^o?

• -330^o, 330^o

• 510^o, -210^o

• 690^o, -30^o

• 420^o, -330^o

Using θ as a reference angle, mark the triangle sides as Opp, Adj, and Hyp. Label these on the triangle on your paper.

• Opp

• x

• Adj

• y

• Hyp

• OP

What is this angle in radians?