Iso angles

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Iso angles

by ravikirancheni » Sat Jan 10, 2009 2:59 am
Am i missing something ???

I DONNO HOW TO TACKLE OPTION B.

PLS HELP.
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iso angles.jpg

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by sparsh.21 » Sat Jan 10, 2009 4:52 am
In Isosceles triangles 2 angles are same.

we need to find the angle R

from 1 angle T is 100 means the measure of the other two angles should be 80 and so angle R is 40 (isosceles triangle ) sufficient.

from 2 angle s is 40 means there are two possibilities
1. s=40 and other 2 angles t=70 r=70
2. s=40 or (t or r =40) and remaining angle is 100
so insufficient.

so the answer is A