Q20. The radii of two concentric circles are 13 cm and 8 cm. AB is a d

1.	Q20. The radii of two concentric circles are 13 cm and 8 cm. AB is a diameter of the bigger circleand BD is a tangent to the smaller circle touching it at D and intersecting the larger circle atP on producing. Find the length of AP
Answer» R= 8cmR=13cmangle ODB= 90 degrees ( BD is tangent)angle APB =90 degrees ( angle in semicircle)angle DB0 =ANGLE PBA (COMMON) SO, BY AA criteria tri APB similar to tri DBO BY CPST ...... BD/BP=BO/AB= OD/ APOD/AP= BO/AB8/AP=13/26AP=16 cm

Q20. The radii of two concentric circles are 13 cm and 8 cm. AB is a diameter of the bigger circleand BD is a tangent to the smaller circle touching it at D and intersecting the larger circle atP on producing. Find the length of AP

Answer»

R= 8cmR=13cmangle ODB= 90 degrees ( BD is tangent)angle APB =90 degrees ( angle in semicircle)angle DB0 =ANGLE PBA (COMMON)

SO, BY AA criteria tri APB similar to tri DBO BY CPST ...... BD/BP=BO/AB= OD/ APOD/AP= BO/AB8/AP=13/26AP=16 cm