What a deviously misleading diagram.
The triangle on the left isn’t actually a right angle triangle, as the other angles add to 100°, meaning the final one is actually 80°, not 90°.
Therefore the triangle on the right also isn’t a right angle triangle. That corner is 100°.
100+35=135°. 180-135=45°. So that’s 45° for the top angle.
X = the straight line of the joined triangles (180°) - the top angle of the right triangle (45°). 180-45=135°
X is 135°, not the 125° it initially appears to be.
It also doesn’t say that the line on the bottom is straight, so we have no idea if that middle vertex adds up to 180 degrees. I would say it is unsolvable.
This is what I was thinking. The image is not to scale, so it is risky to say that the angles at the bottom center add up to 180, despite looking that way. If a presented angle does not represent the real angle, then presented straight lines might not represent real lines.
Eh, I think @sag pretty well nailed it.
Looks like an outer triangle with inner triangles so x = 180 - (180 - (40 + 60 + 35)) = 40 + 60 + 35 = 135
The person who made it needs this:
https://www.explainxkcd.com/wiki/index.php/169:_Words_that_End_in_GRY
I don’t know if that helps or not.
It literally explains it in the comic? People who communicate badly and then act smug when they’re misunderstood are annoying. The other user is saying that the same applies to the OPs post; because the angles don’t match the graphic, they’re communicating badly
It’s a geometry puzzle. Of course they aren’t going to get out a protractor to carefully get the 80° drawn to scale. The point of these puzzles isn’t that we actually want to know what the angle is. The point is to navigate a maze of logic. (A very short maze in this particular case.)
All these people saying its 135 are making big assumptions that I think is incorrect. There’s one triangle (the left one) that has the angles 40, 60, 80. The 80 degrees is calculated based on the other angles. What’s very important is the fact that these triangles appear to have a shared 90 degree corner, but that is not the case based on what we just calculated. This means the image is not to scale and we must not make any visual assumptions. So that means we can’t figure out the angles of the right triangle since we only have information of 1 angle (the other can’t be figured out since we can’t assume its actually aligned at the bottom since the graph is now obviously not to scale).
Someone correct me if I’m wrong.
135 is correct. Bottom intersection is 80/100, 180-35-100 = 45 for the top of the second triangle. 180 - 45 = 135
Mathematician here; I second this as a valid answer. (It’s what I got as well.)
Random guy who didn’t sleep in middle school here: I also got the same answer.
You’re making the assumption that the straight line consisting of the bottom edge of both triangles is made of supplementary angles. This is not defined due to the nature of the image not being to scale.
Unless there are lines that are not straight in the image (which would make the calculation of x literally impossible), the third angle of the triangle in the left has to be 80°, making the angle to its right to be 100°, making the angle above it to be 45°, making the angle above it to be 135°. This is basic trigonometry.
I mean, the assumption shouldn’t be anything about scale. It should be that we’re looking at straight lines. And if we can’t assume that, then what are we even doing.
But, assuming straight lines, given straight lines you find the other side of an intersecting line because of complements.
And if we can’t assume that, then what are we even doing
That’s exactly what the other user is saying. We can’t assume straight lines because the given angles don’t make any sense and thus this graph is literally impossible to make. We’re arguing over literal click bait is what we’re doing.
We can’t assume that the straight line across the bottom is a straight line because the angles in the drawing are not to scale. Who’s to say that the “right angle” of the right side triangle isn’t 144°?
If the scale is not consistent with euclidian planar geometry, one could argue that the scale is consistent within itself, thus the right triangle’s “right angle” might also be 80°, which is not a supplement to the known 80° angle.
I’d argue that the bottom line is indeed one continuous line regardless of how many other lines intersect on it, because there’s nothing indicating that the line is broken at the intersection.
Now the only reason I think the lines are straight at all is use of the angular notations at the ends, which would be horribly misleading to put at the end of curves or broken lines.
Stupid stuff like this is why kids hate math class. Unless the problem says calculate all unmarked angles, those visually 90 degree angles are 90 degrees. It works that way in any non engineering job that uses angles because it’s common sense.
…what? I get that this drawing is very dysfunctional, but are you going to argue that a triangle within a plane can have a sum of angles of 190°?
Nope I’m not saying that. I’m saying this is a gotcha question that demotivates learners.
No, they’re saying that unless you’re already good at this stuff, it’s easy to assume that a visually 90° angle is actually 90° even when it’s not
Your assumption is that it’s a Cartesian coordinate system with 90° angles. But that’s not necessarily the case. You can apply a sheer transformation to correct for the unusual appearance. When you do that, the angles change, but straight lines stay straight and parallels stay parallel. There’s a mathematical term for that, which I can’t remember right now.
135
It pisses me off to no end that what is CLEARLY shown as a 90degree angle is not in fact 90deg, I hate it when they do that.
Also I will sadly admit this can teach people lessons about verifying the information themselves.
GrumbleGrumbleGrumble…
Geometry diagrams in math problems should never be assumed to be to scale
I get you, but it doesn’t clearly indicate the angle in the middle at the base as much as it suggestively waggles its eyebrows towards 90⁰, it could just as easily be 89.9999999999999⁰, although upon zooming in, you can see the line does shift one pixel over on its way up. You simply can’t trust any of the angles as 90⁰ unless it’s got the ∟ symbol (that’s the official unicode) or you’ve measured them yourself, and with that one pixel off-set, it’s decidedly not 90⁰. That’s why you have to do the math.
The internal angles of a triangle always add up to 180⁰, therefore the one pixel offset is irrelevant because the unlabelled angle is, despite what the image suggests, 60 80⁰.
Another way to look at it is that it is simply a representation of an object. We don’t need to visualize the angles, as the values to the other asks are given. We just need the geometry of the object represented so we can calculate the value of the unlabeled angle. Given that the geometry of the objects is represented as triangles, we can infer that all sides are straight lines, regardless of the type of space the object occupies.
trash diagram too, the 90 degree looking center angle is actually 80 on the left, 100 on the right.
180 - (100 + 35) = y
x = 180 -y
I can’t be assed to do the simple math
trash diagram too
A lot of those standardized tests like SAT or GRE like to put those in (or at least they used to) on purpose. It wasn’t that they couldn’t render the diagrams correctly, instead they were checking for people making assumptions with information that wasn’t given. To be somewhat fair I seem to recall a disclaimer that they weren’t necessarily drawn accurately.
I like that all the comments are people discussing the diagram.
