what is trigonometry?
Trigonometry can be thought of as the calculation part of geometry. It is where you apply your knowledge of triangles and use the resulting formulae to help you solve problems.
The first part of the word "trigon" is the Greek word for triangle and the root word "metron" is Greek for measure. So as you probably already deduced, trigonometry has a lot to do with triangles! The trigonometric functions of sine, cosine and tangent all come from measuring the triangle.
Trigonometry is all about the ratios between the sides of a triangle, in particular, a right-angle triangle. Sine, cosine and tangent are all different ratios between these three sides.
The first part of the word "trigon" is the Greek word for triangle and the root word "metron" is Greek for measure. So as you probably already deduced, trigonometry has a lot to do with triangles! The trigonometric functions of sine, cosine and tangent all come from measuring the triangle.
Trigonometry is all about the ratios between the sides of a triangle, in particular, a right-angle triangle. Sine, cosine and tangent are all different ratios between these three sides.
Trigonometry and triangles
The trigonometric ratios of sine, cosine and tangent are the foundation of trigonometry. All other trigonometric functions are related to these basic three functions.
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Trigonometry and circles
So how are triangles related to circles? Well, when you travel around a circle you can create all the triangles you need to solve trigonometry problems.
A circle with a radius of one is called a "unit circle". We can place the circle on the Cartesian plane with the centre of the circle as the origin (0,0). |