Soh Cah Toa Unit Circle

What type of triangles do you use the trig ratios with?

• any type

• right triangle

• obtuse triangle

• acute triangle

Find sin 45° (make sure to rationalize)

• √2

• √2 /2

• 1/2

• √3/2

Find tan 45°

• √2/2

• √3

• 1

• √3/3

Find sin 30°

• √2

• √2 /2

• 1/2

• √3/2

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.

• Hyp

• x

• Adj

• OP

• Opp

• y

• undefined

Answer explanation