mgmat city - triangles

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Source: — Data Sufficiency |

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by kvcpk » Sat Jul 17, 2010 2:27 am
pradeepkaushal9518 wrote:In the figure, angle C and angle M are right angles, and KL = 10. If the area of triangle ABC is four times the area of triangle KLM, what is the length AB?

(1) Angles ABC and KLM have the same measure.

(2) LM is 6 inches.
Can u please load the picture in a word doc and attach?

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by pradeepkaushal9518 » Sat Jul 17, 2010 3:27 am
these are simple triangles with c and M as right angles

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by Rahul@gurome » Sat Jul 17, 2010 3:46 am
pradeepkaushal9518 wrote:In the figure, angle C and angle M are right angles, and KL = 10. If the area of triangle ABC is four times the area of triangle KLM, what is the length AB?

(1) Angles ABC and KLM have the same measure.

(2) LM is 6 inches.

(1) Angle ABC = Angle KLM implies Angle CAB = Angle MKL
So, triangles ABC and KLM are similar.
Since, Area of triangle ABC = 4 (Area of triangle KLM) so each side of triangle ABC is two times the sides of triangle KLM.
Hence AB = 2(10) = 20.

So, (1) is SUFFICIENT.

(2) LM = 6 in, using which we can find KM. If we know KM we can find the area of triangle KLM, but using that we can only find the area of triangle ABC, but not the length AB.
So, (2) is NOT SUFFICIENT.

The correct answer is [spoiler](A)[/spoiler].

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by singhpreet1 » Sun Jul 18, 2010 12:50 am
pradeepkaushal9518 wrote:these are simple triangles with c and M as right angles
assuming u mean Similar triangles.

Preet