sashiim20
On the rectangular coordinate plane, points \(P\), \(Q\), and \(R\) form a right triangle with two sides that are parallel to the \(x\) and \(y\) axes. If point \(P\) is located at \((-3, 2)\), point \(R\) is located at \((3,-6)\), and the \(90\) degree angle is at point \(Q\), what is the perimeter of triangle \(PQR\)?
(A) 10
(B) 12
(C) 14
(D) 17
(E) 24
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I agree with
KJags (kudos given!) :
Even without graph paper, this triangle is easy to draw.
Sketch, and list the coordinates of P and R.
Draw a straight line to the right from P and a straight line up from R.
The two lines meet at right-angled vertex Q.
Q's x-coordinate is the same as R
Q's y-coordinate is the same as P
Q is at (3,2)
Find the length of the sides PQ and QR
I don't like the distance formula; I find it cumbersome and prone to error.
Either count the length of each leg (PQ = 6 and QR = 8), OR
Find length of PQ by subtracting x-coordinates: 3 - (-3) = 6
Find length of QR by subtracting y-coordinates: 2 - (-6) = 8
This is a 3-4-5 right triangle, so 6: 8:
10 = hypotenuse = length of PR*
Perimeter is 6 + 8 + 10 = 24
Answer E
*Alternatively use Pythagorean theorem:
\(6^2 + 8^2 = (PR)^2\)
\(100 = (PR)^2\)
\(PR = 10\)Add sides for perimeter