Question

two concentric circles with Centre o are of radius 6 cm and 3 cm from an external point P tangents PA and PB are drawn to the circles as shown in figure if ap is equal to 10 cm find BP

Answer 1

Answer:

In ΔOAP is a right angle at A then,

where, OA = 5 cm, OB = 3 cm and AP = 12 cm

OP^2 = OA^2 + AP^2

OP^2 = (5)^2 + (12)^2

OP^2 = 25 + 144 = 169

OP = 13 cm

In ΔOBP is a right angle at A then

OP^2 = OB^2 + BP^2

(13)^2 = (3)^2 + BP^2

169 = 9 + BP^2

BP^2 = 160

BP = 4√10 cm.

∴ length of BP = 4√10 cm.