Multiple choice

Tangent drawn from a point X, touches the circle at U.O is the center of this circle. If XU=15 cm and OU=8 cm, then what is the value of OX ?

  1. 12 cm

  2. 19 cm

  3. 21 cm

  4. 17 cm

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

By the tangent-radius theorem, XU is perpendicular to OU at point U. Triangle XUO is right-angled at U. Using Pythagoras: OX² = XU² + OU² = 15² + 8² = 225 + 64 = 289. Therefore OX = √289 = 17 cm.