Take an x-axis and an y-axis (orthonormal) and let O be the origin.
A circle centered in O and with radius = 1, is called a trigonometric circle or unit circle.
Turning counter clockwise is the positive orientation in trigonometry.
Angles are measured starting from the x-axis.
Two units to measure an angle are degrees and radians
An orthogonal angle = 90 degrees = pi/2 radians
In this theory we use mainly radians.
With each real number t corresponds just one angle, and just one point P on the unit circle, when we start measuring on the x-axis. We call that point the image point of t.
Area of a triangle
The area of the triangle is a.h/2 .
A circle centered in O and with radius = 1, is called a trigonometric circle or unit circle.
Turning counter clockwise is the positive orientation in trigonometry.
Angles are measured starting from the x-axis.
Two units to measure an angle are degrees and radians
An orthogonal angle = 90 degrees = pi/2 radians
In this theory we use mainly radians.
With each real number t corresponds just one angle, and just one point P on the unit circle, when we start measuring on the x-axis. We call that point the image point of t.
Area of a triangle
The area of the triangle is a.h/2 .
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