Explanation for Question 5 From the Math (No Calc) Section on the 2019 May Sat
So question five says in the figure above line T intersects 2 lines, L and K, which of the following statements, 3 if true, when implied that lines L and K are parallel. 4 So before we even look at the answer choices, 5 uh, we should recognize that this is testing angle rules. 6 So let's just quickly do a review of those angles. 7 So if you have two lines that intersect each other, 8 like this, the angles across from each other. 9 So for example, a and C are equal to each other, 10 the angles that are adjacent to each other. 11 So a and B for example, add together to equal 180. 12 Now, if you have two sets of parallel lines that intersect the same 13 line, then these rules can be used to find the angles of these bottom 14 four angles. That's because a is going to be equal to this 15 angle right here. 16 And this angle right here. And so is C whereas B and D are 17 going to be equal to these lines right here and 18 here. I like to imagine it as just moving up this section here 19 to be directly on top of the other set of angles and just use 20 the same rules that you would use to find out the measures of the 21 upper angles. So now that we've reviewed those angle rules, 22 let's go through the answer choices that we have. So first w is equal 23 to Y. So if w is equal to Y, 24 that would make sense because they are angles that are across from each other, 25 but it wouldn't tell us anything about this bottom section right here. 26 And therefore it wouldn't tell us that L and K a...