Radian Unit Circle

• -1/2

• 1/2

• √3/2

• -√3/2

What is the reference angle?

• 163

• 73

• 27

• 107

What is the reference angle?

• 48

• 138

• 132

• 42

Find the reference angle.

Find the reference angle.

How will we use the unit circle?

• It will be like a calculator (gives exact values)

• To help us draw triangles

• To help us draw sections of a circle

• To measure the angles of objects

What is the radius of a unit circle?

• 1

• 2

• 1/2

• 0

• 0

• 1/2

• √3/2

• 1

What is sin 45°?

• 1

• ^√3/₂

• ½

• ^√2/₂

What is cos 90°?

• ½

• undefined

• 1

• 0