In fig. from an external point P. PA and PB are tangents to the circle

1.	In fig. from an external point P. PA and PB are tangents to the circle with centre O.If CD is another tangent at point E to the circle and PA-12 cm. Find the perimeter of ∆ PCD
Answer» Given :PA and PB are tangent to the circlewith centre O. CD is a tangent to the circle at E which intersects PA and PB in C and Drespectively and PA = 12 cm. Lengths oftangents drawn from as external point to a circle are equal. ∴ PA = PB = 12 cmCA = CEDB = DENowperimeter of ΔPCD = PC + CD + PD = PC + (CE+ ED) + PD = PC + (CA+ DB) + PD = (PC +CA) + (DB + PD) = PA + PB = 12 cm +12 cm= 24 cm.

In fig. from an external point P. PA and PB are tangents to the circle with centre O.If CD is another tangent at point E to the circle and PA-12 cm. Find the perimeter of ∆ PCD

Answer»

Given :PA and PB are tangent to the circlewith centre O.

CD is a tangent to the circle at E which intersects PA and PB in C and Drespectively and PA = 12 cm.

Lengths oftangents drawn from as external point to a circle are equal.

∴ PA = PB = 12 cmCA = CEDB = DENowperimeter of ΔPCD = PC + CD + PD

= PC + (CE+ ED) + PD

= PC + (CA+ DB) + PD

= (PC +CA) + (DB + PD)

= PA + PB

= 12 cm +12 cm= 24 cm.