Question

In Fig. 10.90, PR =
A. 20 cm
B. 26 cm
C. 24 cm
D. 28 cm

Answer 1

Answer:

answer is 26

100℅sure

.....

Answer 2

The length PR can be calculated by adding the total length of PO, OO’ and O’R. You also need to use Right angled triangle formula to calculate the length of PO and O’R.

Explanation:

Here let us say that the two circles meet at Point T.  

So we have OT + TO’ = OO’.

Also keep in mind that OQ = OT = 3 cm (radius of same circle).

And, SO’ = O’T = 5 cm (radius of big circle).

Now ∆POQ is right angled at Q and PO is the Hypotenuse.

So PO^2 = PQ^2 + QO^2.

PO^2 = 4^2 + 3^2

PO^2 = 16 + 9

PO^2 = 25  

PO = √25 = 5 cm.

Now in ∆RSO’ (it is right angled at S).

So, RO’ is the Hypotenuse.

So, RO’^2 = RS^2 + SO’^2

     RO’^2 = 12^2 + 5^2

RO’^2 = 144 + 25

RO’^2 = 169.

RO’ = √169  

 RO’ = 13 cm.

Now, we know that PR = PO + OT + TO’ + O’R

        PR = 5 + 3 + 5 + 13

        PR = 26 cm.

So, here the correct answer is Option B.