5 1 Angles and Radian Measure ANGLES Ray

5. 1 Angles and Radian Measure

ANGLES • Ray – only one endpoint • Angle – formed by two rays with a common endpoint • Vertex – the common endpoint of an angle’s initial and terminal sides. -Vertex @ origin -Initial side lies along positive x-axis

QUADRANTS When in standard position, an angle’s terminal side lies in a quadrant.

Quadrantal Angle Not in a quadrant. Terminal side is on either the x- or y-axis.

MEASURING ANGLES USING DEGREES • Acute • Right • Obtuse • Straight

MEASURING ANGLES IN RADIANS • One radian is the measure of the central angle of a circle that intercepts an arc equal in length to the radius of the circle.

Ex #1: RADIAN MEASURE •

MEASURING ANGLES IN RADIANS • One radian is the measure of the central angle of a circle that intercepts an arc equal in length to the radius of the circle.

Plus just a little bit more!

Radians and Degrees •

CONVERSION •

Drawing Angles in Standard Position •

Drawing Angles in Standard Position •

UNIT CIRCLE

FINDING COTERMINAL ANGLES

HOMEWORK • Pg. 480 #1 -55 odd + pg. 476 Checkpoint #5 (you’ll need to read Example 5 in order to do the checkpoint)