Explanation for Question 30 From the Math (Calc) Section on the Official Sat Practice Test 10
Now we're looking at question number 30, 2 which tells us the AED is parallel to BC and that C D so 3 the, this length right here is one half of this length here. 4 So that means that if I call this X and it's one half of 5 the longer length, then this one is going to be two X, 6 right? Because X is one half of two X. 7 All right. So now it wants to know what is the measure of angle 8 B? What is this angle measurement? 9 And so the first thing that I'm noticing is that this, 10 sure, this is a, a para not parallelogram. 11 This is a traffic Lloyd, but I can also create a triangle 12 out of it. Imagine that I took this side here and I pushed it 13 this way. So they had a new side length right here, 14 and it still be the same length. 15 Right. Um, but there would just be in an X there instead of 16 on this back end. And this is a really special relationship. 17 The fact that the hypotony uses two times one of the side lengths, 18 that's a special 30, 60, 90 triangle. 19 Um, when the, when the hypotony news is to, 20 uh, is two times one of the side blanks, 21 you have a 30, 60, 90 triangle, 22 right? And so that means this side is going to be 60 this side. 23 Um, oh my apologies. 24 This side is going to be 30. This side is going to be sick. 25 And so I'll go ahead and explain a little further why I knew to 26 put the, um, the angle measures where I put them is because this side 27 is X, route three, this is the, um, 28 this is the 30, 60, 90 kind of like cheat sheet for the t...