QUADRANTS: Quarters on a coordinate plane.

ANGLE: Two sides joined at a vertex make up an angle~ Three parts: initial side, terminal side, vertex

STANDARD POSITION: When putting an angle on the coordinate grid, the initial side lays on the positive x axis, and the vertex on the origin

POSITIVE ANGLES: Terminal side moves in COUNTERCLOCKWISE directionNEGATIVE ANGLES: Terminal side moves in a CLOCKWISE directionDEGREES: Unit of measurement for interior angle of a circle; 360o total in a circle

RADIANS: Units of measurement for the arc length of a circle circumference: 2π radians total in a circle

CONVERTING BETWEEN RADIANS ↔ DEGREES1.) To convert from DEGREES to radians: Multiply degrees given by

1.) To convert from RADIANS to degrees; Multiply radians given by

COTERMINAL ANGLES: Let a be an angle measurement, then a and a + 360b are coterminalLet a be a radian measurement, then a and a + 2bπ are coterminal

Radians in QuadrantsQuadrant I: and 0 - radians

Quadrant II: and - radians

Quadrant III: and

Quadrant IV: and

Initial side

Term

inal sid

e

Vertex

o180

o180

oo 900 21

oo 18090 21

oo 270180 23

0/223 oo 0/360270