Radians Degrees Reference Angles

Front

What is a radian?

Back

A radian is a unit of angular measure used in mathematics, defined as the angle subtended at the center of a circle by an arc equal in length to the radius of the circle.

Front

How do you convert degrees to radians?

Back

To convert degrees to radians, multiply the degree measure by π/180.

Front

How do you convert radians to degrees?

Back

To convert radians to degrees, multiply the radian measure by 180/π.

Front

What is a reference angle?

Back

A reference angle is the smallest angle that a given angle makes with the x-axis, always measured as a positive angle.

Front

Find the reference angle for an angle measuring 310°.

Back

50°

Front

Find the reference angle for an angle measuring θ = 7π / 5.

Back

2π / 5

Front

Convert from radians to degrees: 7π / 4.

Back

315°

Front

Convert 270 degrees to radians.

Back

3π/2

Front

What is the reference angle for 240 degrees?

Back

60 degrees

Front

What is the reference angle for 150 degrees?

Back

30 degrees