Page 6 - Ebook Trigonometri_Krisna Hasugian_MESP 2019
P. 6
UNDERSTAND HOW ANGLES ARE MEASURED
Since Trigonometry focuses on relationships of sides and angles of a triangle, let’s
go over how angles are measured…
Angles are formed by an initial side and a terminal side. An initial side is said to
be in standard position when it’s vertex is located at the origin and the ray goes
along the positive x axis.
An angle is measured by the amount of rotation from the initial side to the
terminal side. A positive angle is made by a rotation in the counterclockwise
direction and a negative angle is made by a rotation in the clockwise direction.
Angles can be measured two ways:
1. Degrees
2. Radians
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