Question

True or false?
The law of cosines reduces to the pythagorean theorem for right triangles.

Answer 1

It's true

Explanation:

Answer 2

Law of cosine is :
c^2 = a^2 + b^2 − 2ab cos(theeta)
so in case of right triangle , angle is 90 degree:
putting 90 degrees into formula:
c^2 = a^2 + b^2 − 2ab cos(90)
As we know that:
cos90 = 0
c^2 = a^2 + b^2 − 2ab (0)
c^2 = a^2 + b^2 - 0
c^2 = a^2 + b^2 ( this is pythagorean theorem ).
So the above statement is True.