Reference angles, Radians, mixed practice, and Spring!

Front

What is a coterminal angle?

Back

Coterminal angles are angles that share the same terminal side when drawn in standard position. They can be found by adding or subtracting multiples of 360 degrees (or 2π radians).

Front

Find a coterminal angle to -90 degrees.

Back

-450 degrees

Front

What is a reference angle?

Back

A reference angle is the acute angle formed by the terminal side of an angle and the x-axis. It is always positive and less than 90 degrees.

Front

Find the reference angle for an angle measuring θ = 11π / 7.

Back

3π / 7

Front

Which angles are coterminal to 330 degrees?

Back

690 degrees and -30 degrees

Front

What is the reference angle for 455 degrees?

Back

85 degrees

Front

What ancient structure is built facing the sunrise on the first day of spring?

Back

The Great Sphinx

Front

How do you convert degrees to radians?

Back

Multiply the degree measure by π/180.

Front

How do you convert radians to degrees?

Back

Multiply the radian measure by 180/π.

Front

What is the formula for finding a coterminal angle?

Back

Coterminal angle = original angle ± 360n, where n is any integer.