You start from left, and calculate them 1 by 1, based on the angles that you already know. It is quite simple actually, you just have to know they always add up to 180 (within triangle, and when you “split” the space over a straight line).
Yes I originally thought 90 but then noticed the absence of a right angle sign. Also 60+40=100 which means the last angle should be 80. Making that perpendicular 100/80
What a bunch of bullshit. Just draw it way off 90 if you don’t want people to use a protractor. I calculated 125° because of this (but I’m happy I still got the right wrong answer, if that makes sense)
In my geometry classes, it’s only 90 degrees if it’s marked by a right angle marker. Otherwise, no matter how “right” it looks, if you assume before proving, it’s on you.
this is a meme tho. i wanted to treat it like a “real life” problem where if i saw those obviously 90 degree corners, i would just say it’s 90 because nowhere else in all my life outside of stupid schoolwork trick questions would that happen. which meant i got to the answer in a few seconds, which is a handy skill in real life.
You could potentially run into this or something very similar in cad when your sketches aren’t fully defined yet. I’ve definitely ran into models that are slightly off square because someone missed a constraint much earlier in the timeline.
Even if it was a right angle, I think a second assumption is that the top left and bottom lines are equal length, which is also not stated.
I think there’s just not enough information in this picture to calculate the angle, and it can only be determined by measuring. But the image also does not specify that it is drawn to scale.
the lengths are irrelevant. the only info you need to solve this is that a triangle’s internal angles add to 180, and angles on a straight line add to 180
Nope. The value is “undefined”. You don’t have enough info to arrive at 135 - you are assuming that the bottom angle (sum of the angles that touch) is 180 degrees. Since there isn’t a datum saying the bottom “line” is straight, nor does it say the triangle on the right is an isosceles triangle, it is impossible to solve.
I think assuming 2 line segments which make up a larger straight line segment to be parallel is generally accepted practice, and that would trump the angles that are drawn inaccurately.
Of course, it’d be better to put a hash through them both to indicate they’re parallel, especially given the deceptively drawn most-likely-not-a-right-angle.
135° for anyone wondering.
Yes, simple doodle below for anyone wondering.
You start from left, and calculate them 1 by 1, based on the angles that you already know. It is quite simple actually, you just have to know they always add up to 180 (within triangle, and when you “split” the space over a straight line).
you mean to say the right angles aren’t right angles? disgusting, get this outta my sight
this diagram does not provide a right angle indicator, and thus should not be assumed as a right angle
yes that’s the stupid excuse my math teacher would give
evil math teacher laughing in background
correct, just commening the 100/80 intersection looks like 90/90, i think it was intentionally misleading, classic trying to get you problem
Yes I originally thought 90 but then noticed the absence of a right angle sign. Also 60+40=100 which means the last angle should be 80. Making that perpendicular 100/80
What a bunch of bullshit. Just draw it way off 90 if you don’t want people to use a protractor. I calculated 125° because of this (but I’m happy I still got the right wrong answer, if that makes sense)
Its not bulshit, its conventions that make a lot more whole sense later on.
In my geometry classes, it’s only 90 degrees if it’s marked by a right angle marker. Otherwise, no matter how “right” it looks, if you assume before proving, it’s on you.
this is a meme tho. i wanted to treat it like a “real life” problem where if i saw those obviously 90 degree corners, i would just say it’s 90 because nowhere else in all my life outside of stupid schoolwork trick questions would that happen. which meant i got to the answer in a few seconds, which is a handy skill in real life.
You could potentially run into this or something very similar in cad when your sketches aren’t fully defined yet. I’ve definitely ran into models that are slightly off square because someone missed a constraint much earlier in the timeline.
I got 125.
180-(90-35)=x 180-55=x 125=x
You’re assuming it is a right angle
Nothing states that it is
Oh shit you’re right. The left triangles unmarked angle is 80, meaning the right triangles internal angles are 100, 35, and 45. This means X is 135
Even if it was a right angle, I think a second assumption is that the top left and bottom lines are equal length, which is also not stated.
I think there’s just not enough information in this picture to calculate the angle, and it can only be determined by measuring. But the image also does not specify that it is drawn to scale.
the lengths are irrelevant. the only info you need to solve this is that a triangle’s internal angles add to 180, and angles on a straight line add to 180
It isn’t 90 degrees because the image is misleading. 60+40+y=180. y=80
For context: it used to be 675° a few years back so the math checks out.
that’s not how global warming works
ah, the old “we drew a right angle but it represents some other angle” trick. I’ve been burned by that one more times than I can count.
I’d get out my red pen and write: “Bad diagram. -1pt See me after class.”
Nope. The value is “undefined”. You don’t have enough info to arrive at 135 - you are assuming that the bottom angle (sum of the angles that touch) is 180 degrees. Since there isn’t a datum saying the bottom “line” is straight, nor does it say the triangle on the right is an isosceles triangle, it is impossible to solve.
I think assuming 2 line segments which make up a larger straight line segment to be parallel is generally accepted practice, and that would trump the angles that are drawn inaccurately.
Of course, it’d be better to put a hash through them both to indicate they’re parallel, especially given the deceptively drawn most-likely-not-a-right-angle.
I don’t see any indication that this is limited to the Euclidean plane either
Haha, I love this.
Also nothing indicates the numbers are Arabic numerals.
You can’t prove it’s not hexadecimal.