Definitions & Sector/Area Formulas

Angle

• A rotation about a point (vertex)

• It has an Initial Ray and Terminal Ray

Radian

• The central Angle at which the radius is equal to the art length

Standard Position

• On a coordinate plane, vertex is at the origin and the initial ray is on the positive x-axis.

Quadrantal Angles

• Angles in standard position whose terminal ray lies on an axis

Coterminal Angles

• Angles in standard position with the same terminal ray

• Theta

• The Measurement of the Central Angle

• Length of Arc

Radians Relation Arc Length, Radius, Theta

Degrees Relation Arc Length, Radius, Theta

Radians Formula for ArcLength

Degrees formula for Arclength

Radians Sector Area

Degrees Sector Area

Reference Angles

• One side is terminal ray of angle in standard position and the other side is the closest X axis