If the area of triangular region RST
is 25, what is the perimeter of RST?
(1) The length of one side of RST is
5 square root 2.
(2) RST is a right isosceles triangle.
OA is B
Triangle
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(1) The length of one side of RST is 5 square root 2. This is clearly NOT sufficient, as we do not know the measurement of other sides of triangle RST.grandh01 wrote:If the area of triangular region RST
is 25, what is the perimeter of RST?
(1) The length of one side of RST is
5 square root 2.
(2) RST is a right isosceles triangle.
OA is B
(2) RST is a right isosceles triangle.
Let us assume that the two equal sides of triangle RST = x units each
and the hypotenuse = y units
Area of triangle = (1/2) * base * height
25 = (1/2) * x²
x² = 50 implies x = √50
By Pythagoras Theorem, x² + x² = y² or y² = 2x²
So, y² = 2x² = 2 * 50 = 100
y = 10
We know the values of x and y, hence we can find the perimeter of triangle RST; SUFFICIENT.
The correct answer is B.
Last edited by Anurag@Gurome on Sun Aug 19, 2012 10:40 pm, edited 1 time in total.
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- anuprajan5
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Anurag,
I know this can be misconstrued as nitpicking but for B, y = 10 and not y = 10^1/2
Regards
Anup
I know this can be misconstrued as nitpicking but for B, y = 10 and not y = 10^1/2
Regards
Anup
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Thanks for pointing this, have corrected thatanuprajan5 wrote:Anurag,
I know this can be misconstrued as nitpicking but for B, y = 10 and not y = 10^1/2
Regards
Anup
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