Question

Using the Pythagorean Theorem, how do you find the length of a leg of a right triangle if the other leg is 8 feet long and the hypothenuse is 20?

Answer 1

No, the Pythagorean Theorem does not work for non-90 degree triangle. However, there is a more complex version of it that works for all triangles called the Law of Cosines.

Triangle has sides a, b, and c, and angles A, B, and C.

a^2=b^2+c^2-2bc cos(A).

b^2=a^2+c^2-2ac cos(B).

c^2=a^2+b^2-2ab cos(C).

As I said before, the Pythagorean Theorem is a special case of the Law of Cosines where angle C is 90 degrees. The cosine of 90 degrees is 0, so the Law of Cosines simplifies to c^2=a^2+b^2-0, the Pythagorean Theorem.

I think me say the is right