1) 2 of the angles are 90 each, but othere 2 can be (130,50 ) or any thig else. NOT SUFF

2) one angle can be double of other but one of them CAN or CAN Not be 60. like (60,120,50,130) or (50,100, 120,90) so NOT SUFF

considering both, if two angles are 90 each and in other two one is double be other means, X + 2X = 180 => X=60.

Ans : C

Both - C

The answer given in GMAT prep is 'E",

pls explain

Is the measure of one of the interior angles of quadilateral ABCD equal to 60 degrees?


1) Two of the interior angles of ABCD are right angles

90 - 90

so the sum of the other two angles = 180 but we don't know whether it is 60 or not

INSUF

2)The degree of measure of angle ABC is twice the degree of measure of angle BCD[/quote]

This does not mean anything

X , 2X, Y and 180-Y

Together

90 - 45 - 90 - 135 is an option since 90 = 2 x 45

90 - 90 - 60 - 120 is an another option

SO E

Thanks Logitech!