Lesson: Lines and Angles

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Comment on Lines and Angles

knowledgeble video
very nice

At 1:40 in the video how do you know that the line is a straight line (and not bent)?
greenlight-admin's picture

On the GRE, a line that appears to be straight can assumed to be straight. For more on what can and cannot be assumed with GRE Geometry diagrams, see this video: https://www.greenlighttestprep.com/module/gre-geometry/video/863

Hey ! I really did not understand the GRE practice question ( 160 to 170 difficulty level) after r/(r+s)=r/180 ( I didn't understand this part at all) , would you mind explaining it to me again ? is there any other way to approach the problem ?
greenlight-admin's picture

You're referring to this question: http://greprepclub.com/forum/in-the-figure-above-if-what-is-the-value-of...

We're told that r/(r+s) = 5/8

On the diagram, we see that angle r and angle s both lie on the same line, which means they must add to 180 degrees. In other words, r+s = 180

So, we can take the given information, r/(r+s) = 5/8, and replace (r+s) with 180 to get: r/180 = 5/8

To solve this, we can first cross multiply the fractions.
We get: (8)(r) = (5)(180)
Or: 8r = 900
Divide both sides by 8 to get: r = 900/8 = 112.5

Does that help?

Very easy to comprehend tanxs for all your tutorials online you are a good instructor.
greenlight-admin's picture


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