In the given figure, the length of BC is
(a) 7 cm (b) 10 cm (c) 14 cm (d) 15 cm
The correct option is (b): 10 cm
Given: BD=3 cm,AF=4 cm and AC=11 cm
We know that the tangents drawn from an external point are equal.
BF=BD=3 cm (as they are tangents to the circle from external point B)
And, AF=AE=4 cm (tangents from external points A)
AC=AE+EC
⇒11=4+EC
⇒EC=7 cm
Similarly, EC=CD=7 cm (tangents from external point C)
Now, BC=BD+DC
BC=7 cm+3 cm
BC=10 cm