Page 6 - Dhea Anisah Putri_4193111017

Before studying the material for trigonometric comparisons in right triangles, let's work on
the following apperception problems:

2. Angle Measurement

1. Angle measurement in degrees
Degree is the name of the unit used to express the measure of an angle. This

unit is also called the sexagesimal angle unit, which is to divide the circumference

of a circle into 360 equal parts, each part is called 1 degree. Therefore :

∘
1 circle = 1 circumference of circle =360
1 circle = circumference of circle =180
1
∘
2 2
1 1
∘
circle = circumference of circle = 90
4 4
1 circle = 1 circumference of circle = 1
∘
360 360

Therefore, we get:

∘
= circle = circumference of circle

2. Angle measurement in radians
1 Radian is the measure of the angle at the center of a circle whose arc length

in front of it is equal to the radius of the circle.