Question

In Q. No. 1, if PB = 10 cm, what is the perimeter of ΔPCD?

Answer 1

Given: PB = 10 cm. (From an external point P, PA and PB are tangents to the circle.)

Step-wise calculation:

1. Tangents from an external point are equal.

⇒ PA = PB = 10 cm

2. Let CA = x and DB = y.

Then PC = PA − CA = 10 – x

PD = PB – DB = 10 – y

And CD = CE + ED = x + y

3. Perimeter (ΔPCD) = PC + CD + PD 

= (10 – x) + (x + y) + (10 – y)

= 20 cm