Students will use the definition of one radian is the measure of the central angle of a unit circle which subtends (cuts off) an arc of length one to determine measures of other central angles as a fraction of a complete revolution (2π for the unit circle).
Students will use radian measure as a ratio of the arc length to the radius.
Students will be able to accurately find relationships of trigonometric functions for an acute angle of a right triangle to measure within the unit circle.
Students will be able to justify triangle similarity.
Students will be able to find the reference angle for any angle found by a revolution on a ray in the coordinate plane.
Students will be able to relate the trigonometric ratios for the reference angle to those of the original angle.
Students will be able to determine the appropriate sign for trigonometric functions of angles of any given size.