geometry - angle greater

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geometry - angle greater

by Xbond » Mon Aug 03, 2009 10:41 pm
Hi there,

I woud like your input about this difficult geometry question. Someone can explain to me in simple way the concept. Sorry, I don't know the answer. Look at the attachment.


In the figure shown, the measure of angle PRS is how many degrees greater than the
measure of angle PQR ?
(1) The measure of angle QPR is 30°.
(2) The sum of the measures of angles PQR and PRQ is 150°.
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by Gmat09_5ALL » Tue Aug 04, 2009 1:56 am
Answer - A


angle QPR = angle QPS - angle RPS = 30

since in two triangle one angle is 90 -> sum of other two angles would remains 90.

angle PQS + angle QPS = 90
angle SPR + angle PRS = 90

increase in one angle would decrease the other by same degree. Therefore, the different would be 30 degree. Hence A.

Please Correct If I am wrong .

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by mohitsharda » Tue Aug 04, 2009 9:43 am
Gmat09_5ALL wrote:Answer - A


angle QPR = angle QPS - angle RPS = 30

since in two triangle one angle is 90 -> sum of other two angles would remains 90.

angle PQS + angle QPS = 90
angle SPR + angle PRS = 90

increase in one angle would decrease the other by same degree. Therefore, the different would be 30 degree. Hence A.

Please Correct If I am wrong .

Yeah... the explanation is right.... but the answer would be D...
as

if you look at the second statement it says PQR+PRQ= 150

now since this is a triangle... the remaining angle is QPR = 30... which becomes the first condition

So, the answer would be D
MS

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by navalpike » Tue Aug 04, 2009 10:49 am
Math is not necessary for either statement.

As Ian points out in another post, if you simply take the line PR and stretch it out to PQ, you are closing a 30 degree "gap". Thus the difference between the angles will be 30 degrees for S1 as well as S2.

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by Xbond » Sun Aug 09, 2009 8:53 am
the right answer is D