Degrees/Radians, Co-Terminal and Reference Angles

What is the reference angle for -30 degrees?

• 150 degrees

• 30 degrees

• 80 degrees

• 60 degrees

How many RADIANS are in a circle?

• 180^o

• 360^o

• π rad

• 2π rad

The length of an arc is 18cm and the radius of the circle is 6cm. What is the radian measure of the central angle?

• 3 radian

• 2 radian

• 4 radian

• 2π radian

A central angle measure 4.5 radians and has an arc of 35 inches. What is the radius of the circle?

• 7.78 inches

• 8.21 inches

• 157.5 inches

• 7 inches

If you had to evaluate the sin 330 degrees, what is the reference angle you would use?

• 60 degrees

• 30 degrees

• 45 degrees

• None of the above

• 60 degrees

• 30 degrees

• 45 degrees

• None of the above

If you had to evaluate tan \(\frac{3\pi}{4}\), what is the reference angle you would use?

• 60 degrees

• 30 degrees

• 45 degrees

• None of the above

• 90 degrees

• 30 degrees

• 45 degrees

• 60 degrees