Heheheh the 2 triangles are having segs
this post was submitted on 08 Oct 2024
1103 points (98.3% liked)
People Twitter
5061 readers
285 users here now
People tweeting stuff. We allow tweets from anyone.
RULES:
- Mark NSFW content.
- No doxxing people.
- Must be a tweet or similar
- No bullying.
- Be excellent to each other.
founded 1 year ago
MODERATORS
The answer is 125 degrees but the triangle on the left has 190 degrees in it
Nah, the angle isn’t specified as a right angle. We can’t assume it’s 90° just because it’s drawn that way, because it isn’t drawn to scale.
Left triangle has 180° total. 60+40=100, which means that middle line is actually 80°, not 90. And since the opposite side is the inverse, we know it is 100° on the other side.
100+35=135. We know the right triangle also has 180° total, so to find the top corner we do 180-135=45. So that top corner of the right triangle is 45°, meaning x must be 135° on the opposite side.
This is the geometry version of those stupid poorly written math equations. Engagement bait.
The real answer is always "it's unsolveable due to poor/missing notation".
It’s not unsolvable at all. The answer is x=135°. The triangles simply aren’t drawn to scale; The line between them isn’t a 90° angle, (even though it is drawn that way) because it is not specifically marked as 90° with a square angle mark.
But it's not unsolvable, just a misleading drawing...
Either this is drawn wrong or they broke geometry
The triangles aren’t drawn to scale. The middle line isn’t a 90° angle, because it isn’t specifically marked with a square angle in the corner. Triangles always add up to 180°, so the angle in the left triangle is actually 80°, not 90°.
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.
load more comments
(3 replies)
I used to have teacher who deliberately made disproportionate diagrams. His reasoning was that people trust too much what their eyes see and not enough what the numbers tell them. He would've loved that diagram.
load more comments
(15 replies)
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
Yes obviously. But it still irritates me as someone who does geometry for a living.
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.
load more comments
(4 replies)
load more comments
(2 replies)
load more comments
(2 replies)
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.
load more comments
(1 replies)
load more comments
(15 replies)
This is a standard way to draw geometric proofs, it's not at all unreasonable to assume straight lines alongside unrepresentative angles. It's certainly still an assumption, but a conventional one.
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.
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.
load more comments
(7 replies)
load more comments
(10 replies)
The angle formerly known as twitter
Right one does not depend on the left one. 3rd dimension for the win!
load more comments
(3 replies)
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
You mean the simple math of 180 - 180 is too much? Or 100 + 35?
yep. I wasn't paying enough attention
load more comments
(4 replies)
I like that all the comments are people discussing the diagram.
Same.
view more: next ›