True or false?

The law of cosines reduces to the pythagorean theorem for right triangles.

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.