Archive
3rd of March 2017
Mathematics
Q:

O is the centre of the circle, BC = OB, Prove that x = 3y.

Shyam - CBSE - Class IX

Friday, March 03, 2017 at 18:11:PM

A:

begin mathsize 16px style Given space BC equals OB
rightwards double arrow angle BCO equals angle BOC equals straight y

angle OBA equals angle BCO plus angle BOC equals straight y plus straight y equals 2 straight y space... left parenthesis exterior space angle space is space equal space to space sum space of space teh space remote space interior space angles right parenthesis
Since space OA equals OB space... left parenthesis radii space of space the space same space circle right parenthesis
rightwards double arrow angle OAB equals angle OBA equals 2 straight y space... left parenthesis exterior space angle space is space equal space to space sum space of space teh space remote space interior space angles right parenthesis

So comma space in space increment OAC
straight x equals angle OAB plus angle OCA space space... left parenthesis exterior space angle space is space equal space to space sum space of space teh space remote space interior space angles right parenthesis
rightwards double arrow straight x equals 2 straight y plus straight y
rightwards double arrow straight x equals 3 straight y end style

Friday, March 03, 2017 at 22:09:PM