NumericalModerate2 marks
Two chords AB and CD of a circle intersect externally at E. If EC = 2 cm, EA = 3 cm and AB = 5 cm, find the length of CD.
Topic: Tangents / intersecting chords

Previous-year question practice database
Answer
Exam answer
CD = 10 cm
Explanation
By the secant theorem, EA × EB = EC × ED. EB = EA+AB = 8 cm. Thus 3×8 = 2×ED ⇒ ED=12; CD = ED−EC = 10 cm.