In the rectangular coordinate system above, the area of triangular region \(PQR\) is

[VJesus12]

In the rectangular coordinate system above, the area of triangular region \(PQR\) is

(A) \(12.5\)
(B) \(14\)
(C) \(10\sqrt2\)
(D) \(16\)
(E) \(25\)

Answer: A

Source: GMAT Prep

[Brent@GMATPrepNow]

IMAGE PT1.jpg

In the rectangular coordinate system above, the area of triangular region \(PQR\) is

(A) \(12.5\)
(B) \(14\)
(C) \(10\sqrt2\)
(D) \(16\)
(E) \(25\)

Answer: A

Source: GMAT Prep

We're trying to find the area of triangle PQR.



Let's draw a rectangle around the triangle (as shown above) and then subtract from the rectangle's area (28) the areas of the 3 right triangles that surround the triangle in question.

We get the following:


So, the area of PQR = 28 - (3.5 + 6 + 6) = 12.5

Answer = A

Cheers,
Brent