find the missing angle.

Explanation:

Step1: Recall angle - sum property

The sum of angles in a triangle is 180°.

Step2: Set up the equation

Let the missing angle be (x). Then (58^{\circ}+86^{\circ}+x = 180^{\circ}).

Step3: Solve for (x)

First, add 58 and 86: (58 + 86=144). So the equation becomes (144^{\circ}+x = 180^{\circ}). Then (x=180^{\circ}- 144^{\circ}).

Answer:

(36^{\circ})