Answer: The value of x is 12 units.
Step-by-step explanation: We are given to find the value of x from the figure.
We can see that triangle RSQ is a right-angled one with m∠SRQ = 90°. And RT is perpendicular to the hypotenuse SQ.
Given ST = 9 units, TQ = 16 units and RT = x = ?
Since ΔRSQ is a right-angled triangle with hypotenuse SQ and RT is perpendicular to SQ, so we must have

Since the length of a line segment cannot be negative, so the value of of x is 12 units.
Thus, the required value of x is 12 units.