Question

Given: AB tangent to circle O at B, and secant through point A intersect the circle at points C and D. Find CD, if

AB = 4 cm, AC = 2 cm;

Answer 1

6 cm

Explanation:

If you use Tangent-secant product (chapter reference), AB/AC = AD/AB so 4/2 = AD/4. AD = 8, CD = AD - AC = 8 - 2 = 6 cm.