dflorez 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.

Hi,

you are given two right angle triangle and a side of one triangle is given..

Also given is the ratio of ares of two triangles..

we are asked for length of a side of first triangle..

lets see the statement..

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

we are given another angle to be equal ..

now we have two triangles with all three angles same, which means that the two triangles are similar..

In similar triangles, the ratio of area is square of the ratio of corresponding sides ..

it is given four times, so the ratio of sides is two times..

since KL is 10, AB will be 2* 10=20..

suff

(2) LM is 6 inches...

with this info we know what is the area of triangle KLM, and thus the area of ABC, but there will be various combinations of sides to get that area..

insuff..

ans A

_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372

2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html

3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html

GMAT online Tutor