To solve the exercise shown in the figure attached, you must apply the proccedure shown below:
1. You must apply the Tangent Secant Segment Theorem, as following:
ST²=QTxRT
2. Now, solve for ST:
ST=√(QTxRT)
3. Subtitute the values:
ST=√(23+7)(7)
ST=14.49 inches
The anwers is: 14.49 inches.