What are trigonometric ratios?
In this post, we use the sine, cosine, and tangent ratios to solve problems involving right-angled triangles where angles are measured in degrees, or degrees and minutes, as a part of the Prelim Maths Advanced course under the topic Trigonometric Functions and sub-part Trigonometry. To define trigonometric ratios, we will use a right-angled triangle, and we refer to the ratio of two different sides according to how they are placed in relation to the angle \theta . To remember our trigonometric ratios, we use SOHCAHTOA. So:
- SOH: sin(\theta) = \frac{opposite}{hypotenuse}
- CAH:Â cos(\theta) = \frac{adjacent}{hypotenuse}
- TOA:Â tan(\theta) = \frac{opposite}{adjacent}
What is sin, cos and tan?
This video covers where the theory of sine, cosine, and tangent, and their respective ratios by using SOHCAHTOA.
How do I use trigonometry to solve right angle triangle questions?
This video runs over some examples of using trigonometry to solve questions involving right-angled triangles, with a clear explanation of how to approach and set out your working.
