Question

BRAINLIEST ANSWER TO FIRST ANSWERER!!!

Answer 1

Answer:

23

Step-by-step explanation:

just took the test on apex

Answer 2

Answer:

Option B is correct i.e, $23^{\circ}$

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;

$\cos C = \frac{a^2+b^2-c^2}{2ab}$

$\cos A = \frac{b^2+c^2-a^2}{2bc}$

$\cos B = \frac{c^2+a^2-b^2}{2ca}$

Given triangle ABC is right angle triangle.

Law of cosines for this triangle is,

$b^2+c^2-2bc\cos A = a^2$

since,$\angle A = 23^{\circ}$ , $\angle B = 90^{\circ}$ and $\angle C= 67^{\circ}$.

then,

$12^2+13^2-2(12)(13)\cos 23^{\circ} = 5^2$