Category: 2. Basic Trigonometry

Trigonometry is also useful for general triangles, not just right-angled ones . It helps us in Solving Triangles. “Solving” means finding missing sides and angles. Example: Find the Missing Angle “C” Angle C can be found using angles of a triangle add to 180°: So C = 180° − 76° − 34° = 70° We can also find missing side…

Because the angle is rotating around and around the circle the Sine, Cosine and Tangent functions repeat once every full rotation (see Amplitude, Period, Phase Shift and Frequency). When we want to calculate the function for an angle larger than a full rotation of 360° (2π radians) we subtract as many full rotations as needed to bring it back below 360°…

What you just played with is the Unit Circle. It is a circle with a radius of 1 with its center at 0. Because the radius is 1, we can directly measure sine, cosine and tangent. Here we see the sine function being made by the unit circle: Note: you can see the nice graphs made by…

The main functions in trigonometry are Sine, Cosine and Tangent They are simply one side of a right-angled triangle divided by another. For any angle “θ“: (Sine, Cosine and Tangent are often abbreviated to sin, cos and tan.) Example: What is the sine of 35°? Using this triangle (lengths are only to one decimal place): sin(35°) = OppositeHypotenuse = 2.84.9 = 0.57……

Why is this triangle so important? Imagine we can measure along and up but want to know the direct distance and angle: Trigonometry can find that missing angle and distance. Or maybe we have a distance and angle and need to “plot the dot” along and up: Questions like these are common in engineering, computer…

The triangle of most interest is the right-angled triangle. The right angle is shown by the little box in the corner: Another angle is often labeled θ, and the three sides are then called:

Trigonometry (from Greek trigonon “triangle” + metron “measure”) Trigonometry … is all about triangles. Trigonometry helps us find angles and distances, and is used a lot in science, engineering, video games, and more!