Brainliest answer to first ! select the angle that correctly completes the law of cosines for this triangle. 12^2+13^2-2(12)(13)cos__=5^2 answers in pic.

Option B is correct i.e,

Explanation:

Law of cosine is useful to find:

* The third side of a triangle when we know two sides and angle between them.

* The angles of a triangle when we know all three sides.

It can be either of these forms;

Given triangle ABC is right angle triangle.

Law of cosines for this triangle is,

since, , and .

then,

the answer is:

the answer is:

to solve the problem, we need to remember the quotient of power property, it's defined by the following relation:

if we have a quotienf of powers that have the same base, we need to keep the same base and subtract the exponent of the denominator power to the exponent of the numerator power.

so, we are given the expression:

then, calculating we have:

hence, the answer is:

have a nice day!