Question

Find x. Round to the nearest degree.

Answer 1

When the three sides of a triangle is known and you are looking for one of the angles, you make use of the cosine formular which states that
`\cos A= ( b^(2) + c^(2) - a^(2) )/(2bc)`; where A is the angle you are looking for (i.e. in this case x), a is the side opposite the angle you are looking for and b & c are the other sides of the triangle.
Therefore,
`\cos x^o= ( 36^(2) + 59^(2) - 39^(2) )/(2 * 36 * 59)= (3,256)/(4,248) =0.7665 \\ x^o=\cos^(-1)0.7665=40^o`