gmat prep geo

vinviper1 · Posted: Thu Aug 28, 2008 11:01 am Post subject: gmat prep geo

Thanks!

sumithshah · Posted: Thu Aug 28, 2008 11:45 am Post subject:

A is fine- whats the OA?

bomond · Posted: Thu Aug 28, 2008 12:05 pm Post subject:

The opposite sides of the same angles are equal. From this point of view ST 1 is sufficient.

kshankker · Posted: Thu Aug 28, 2008 9:55 pm Post subject:

Yeah A is correct....st 1- tells u that side =6.since it is isoscel. it is sufficient to ans. in st 2 it doesnt mention any length - hence it is insufficient

pepeprepa · Posted: Fri Aug 29, 2008 3:02 am Post subject:

1)
You know BD=BC given BCD is isocele.
You have AD and you want to make a link with BC.
Angle DBC=180-4x
Angle ABC=180-3x
Join both equations with that:
Angle ABC= Angle ABD + Angle DBC
180-3x=Angle ABD + 180-4x
Angle ABD=x
So Angle ABD=Angle BAD so ABD is an isocele triangle
And AD=BD=BC=6

2) does not give you information about the sides.