Question

I would like you to help me with that since I do not understand very well please ​

Answer 1

When you see the symbol "△", this denotes a triangle. Now combine the symbol with the letters FGH, this becomes △FGH, meaning a triangle FGH, with F, G, and H as the three points.

Now, the symbol "∠" means angle and "m∠" means the measure of an angle. So m∠F means the angle at the point F, m∠G means the angle at the point G, and m∠H means the angle at the point H. (I'll attach a diagram of this triangle).

Now we have to determine m∠H, which is the angle at point H. To do that, we have to find the value of $x$. To do that, we have to use one of the laws of a triangle, which is:

The sum of angles in a triangle = 180°. This means when we add all the angles in a triangle, it sums up to 180°. Let's do that.

$\angle F + \angle G + \angle H = 180\textdegree \\\angle F = (5x - 6)\textdegree, \angle G = (3x + 16)\textdegree, \angle H = (x + 8)\textdegree \\(5x - 6) + (3x + 16) + (x + 8) = 180\\5x + 3x + x - 6 + 16 + 8 = 180\\9x + 18 = 180\\9x = 180 - 18\\9x = 162\\x = 18\textdegree$

Now that we have found the value of x as 18°, we can substitute its value to determine the angle H.

$m\angle H = (x + 8), x = 18\\m\angle H = 18 + 8\\m\angle H = 26\textdegree$

I hope you understand the explanation.