If the degree measures of two angles of an...

Hi swerve,

We're told that two angles of an ISOSCELES triangle are in the ratio 1:3. We're asked for the degree measure of the LARGEST angle if it is not a base angle.

Since we're dealing with an ISOSCELES triangle, we know that two of the angles are the SAME. Thus, the ratio of the angles is either 1:1:3 or 1:3:3. We're told that the largest angle is NOT one of the two base angles, so we're dealing with the first possibility (in which the angles can be referred to as X, X and 3X). In that triangle we have....

5X = 180 degrees
X = 36 degrees
The three angles are 36, 36 and 108

Final Answer: E

GMAT assassins aren't born, they're made,
Rich