Oblique Triangles

Oblique Triangles are triangles that are not right triangles. They can be solved by the Law of Sines.

The Area for Oblique Triangles can be solved my using h, but then substituting it with something we know is true.

For example: 

Solve by cross multiplying



Reference Angles

A Brief Journey Into The Magic Of Reference Angles





"If A is an angle in standard positon, its reference angle is the acute angle formed by the x axis and the terminal side of angle A."

-Dr Abdelkader Dendane, PH.D applied Mathematics



In layman's terms, it's the angle between A (or θ) and the nearest x axis. It is ALWAYS acute; if the angle θ is in the second quadrant, the reference angle is computed by subtracting θ from 180 degrees (180 - θ); third quadrant, by subtracting 180 from θ (θ-180); and fourth quadrant, by subtracting θ from 360 degrees (360 - θ). If the angle θ is located in the first quadrant, there is no math to be done as in that case angle θ is equal to its own reference angle.



Above is a basic illustration of reference angles.