__maths__>__Advanced Trigonometry__>__Trigonometric Values for all angles in unit circle form__### Trigonometric Values in Four Quadrants

This page explains the quadrants, various angles in different quadrants, trigonometric ratios of such angles.

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2D coordinate plane is split into four quadrants. Four Quadrants are numbered as I, II, III, and IV as shown in the figure.

The word "quadrant" means quarter of a plane. The word "Quadrant" is derived from one fourth or quarter.

Consider angle `150^@`. `sin 150^@` can be computed for line on unit circle at `/_150^@`. The projection of the line on x and y axes defines the trigonometric ratios.

Similarly, `sin(-30^@)` can be computed for line of unit circle at `-30^@` angle. The projection of the line on x and y axes defined the trigonometric ratios.

The projection of line on x and y axes can be positive or negative. So the trigonometric ratios can be positive or negative.

Trigonometric Ratios can be calculated for any angle between `-oo` and `oo` and the value of ratio can be positive or negative.

**Understanding Trigonometric Ratios for any Angle: **Consider the line at the given angle in the unit circle. The projections on x and y axes define the trigonometric ratios. The angle can be between `-oo` and `oo` and the projections can be positive or negative.

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