pacifist85 wrote:

What are the coordinates of point B ?

(1) The area of triangle ABC = 30

(2) Length(CB) = 13

IMPORTANT: For geometry Data Sufficiency questions, we are typically checking to see whether the statements "lock" a particular angle, length, or shape into having just one possible measurement. This concept is discussed in much greater detail in the following video:

http://www.gmatprepnow.com/module/gmat-data-sufficiency?id=1103Target question: What are the coordinates of point B ?NOTE: points A and C are LOCKED in their positions. Since ∠CAB = 90º, we know that point B is SOMEWHERE along the line y = 4. So, some of the MANY possible cases are as follows:

Notice that, for EACH different position of point B, ∆ABC has a different area and side CB has a different length.

Okay, onto the statements...

Statement 1: The area of ∆ABC = 30 As I mentioned above, for EACH different position of point B, ∆ABC has a different area.

So, knowing that the area is 30, LOCKS point B into ONE AND ONLY ONE location.

In other words, statement 1 LOCKS IN the shape/dimensions of ∆ABC, which means

there must be only one location for point B.

As such, statement 1 is SUFFICIENT

Statement 2: Length of CB = 13 As I mentioned above, for EACH different position of point B, side CB has a different length.

So, knowing that side CB has length 13 LOCKS point B into ONE AND ONLY ONE location.

In other words, statement 2 LOCKS IN the shape/dimensions of ∆ABC, which means

there must be only one location for point B.

As such, statement 2 is SUFFICIENT

Answer =

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Brent Hanneson – GMATPrepNow.com