High School · Trigonometric Functions

CCSS.MATH.CONTENT.HSF.TF.A.1

Understand radian measure of an angle as the length of the arc on the unit circle subtended by the angle.

Read this standard on the official Common Core site

Lessons that teach this standard

• Arc Length, Sector Area and Radian Measure

  Why all circles are similar, why an arc's length is proportional to its radius, how that ratio defines the radian, and the formulas for arc length and sector area.