Given:-
Why cant the Pythagorean theorem be used to solve an oblique triangle.
To find the explanation.
The image of the triangle is,
In the above trianlge the pythogoras theorm can be used as,
Simillarly we have,
So in general the every relation ([3],[4],[5]) among three sides is always associated with cosine of one of the angle of the triangle if the triangle is oblique one.