Sasindran wrote:

In the figure CD=2OA=2OB. Find the area of the shaded region

1. ABCD is a square of area 64

2. Product of the diagonals of the square ABCD is 128

CD=2*OA=2*OB..

Means..

OA=OB=radius

CD=DIA..

So area of quarter circle and semi circle combined =Area of circle, with DIA as side of square..

So what we require is the side of the square or distribution of circle..

Let's see what each statement tells us.

1) ABCD is a square of area 64

So side =√64=8

Sufficient

2. Product of the diagonals of the square ABCD is 128

Diagonal of square =side*√2..

Product of diagonals=side^2*√2^2=2*side^2=128.....

Side^2=64

Side=8

Sufficient

D

_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372

2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html

3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html

GMAT online Tutor