The problem asks to find the value of $x$ in a right triangle, where one of the angles is $72^\circ$.

In a right triangle, the sum of the angles must be $180^\circ$. Since one angle is $90^\circ$ (the right angle) and another angle is $72^\circ$, the third angle $x$ can be found as follows:

$x = 180^\circ - 90^\circ - 72^\circ$

$x = 18^\circ$

So, the value of $x$ is $18^\circ$.

Would you like more details on this calculation or have any questions?

Here are 5 related questions for further practice:

1. If the given angle was $45^\circ$, what would the value of $x$ be?
2. What would be the value of the third angle if the given angle was $60^\circ$?
3. How do you calculate the hypotenuse of a right triangle given two angles and one side?
4. Can you find $x$ if one of the angles is $30^\circ$?
5. What is the sum of all angles in any triangle?

Tip: In any triangle, the sum of the interior angles is always $180^\circ$. This property is crucial for solving many geometric problems.