Question

plz help with this prblm

Answer 1

Given AB = AC = 20cm and BC = 24cm.

In a triangle ADB, by Pythagoras theorem, we get

= > AB^2 = AD^2 + BD^2

= > (20)^2 = AD^2 + 1/2(BC)

= > 400 = AD^2 + 1/2(24)

= > 400 = AD^2 + 12^2

= > AD^2 = 400 - 144

= > AD^2 = 256

= > AD = 16

Now,

From triangle OBD, We get

= > OB^2 = OD^2 + BD^2

= > r^2 = (16 - r)^2 + 12^2

= > r^2 = r^2 - 32r + 400

= > 32r = 400

= > r = 400/32

= > r = 12.5.


Hope this helps!

Answer 2

Hi,

Please see the attached file!


Thanks