TW is a radius of this circle.
|TW| = |WQ|
SV = VQ therefore m∠WVQ = m∠WVS = 90°. The triangle QVW is the rectangular triangle.
We calculate the length of WQ using the Pythagorean theorem.
[tex]|WQ|^2=3^2+7^2\\\\|WQ|^2=9+49\\\\|WQ|^2=58\to|WQ|=\sqrt{58}\approx7.62[/tex]
Answer: TW = √58 ≈ 7.62