Multiple choice

PT is a tangent to a circle with Centre O and radius 6 cm. If PT is 8 cm then the length of OP is

  1. 10cm

  2. 12cm

  3. 16cm

  4. 9cm

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

A tangent to a circle is perpendicular to the radius at the point of contact. So triangle OTP is right-angled at T, with OT=6cm (radius) and PT=8cm (tangent). By Pythagoras theorem: OP² = 6² + 8² = 36 + 64 = 100, so OP = 10cm. This is a 6-8-10 Pythagorean triple.