In the given figure, if AB = 10 cm, CD = 7 cm, SD = 4 cm and AS = 5 cm, then BC = ?
Answer & explanation
Correct answer: option 4
From a common point tangents drawn on a circle is of same length.
SD = DR , CR = CQ , BQ = BP & AP = AS
AB = 10 cm, CD = 7 cm, SD = 4 cm and AS = 5 cm
⇒ SD = 4 cm & SD = DR
⇒ DR = 4 cm
It is given that , CD = 7 cm
CR = 7 - 4 = 3 cm
⇒ CR = CQ
⇒ CQ = 3 cm
We know,
AS = 5 cm
AS = AP = 5 cm
Now, BP = 10 - 5 = 5 cm
BP = BQ = 5 cm
Now,
BC = BQ + CQ
= 5 + 3
= 8 cm