I think I remember hearing somewhere that during the French Revolution...

I think I remember hearing somewhere that during the French Revolution, the revolutionaries would leave a mark of the letter V all over, and that it became so prominent and associated with the revolutionaries, everyone knew that if they saw the letter V marked somewhere, the revolutionaries were in the area.
I am very intrigued by this, but I can't find any information on it. And it may not have been the French Revolution, and it may have even been a different letter, but I think it was a V.
Do any of you know anything about this, or where I could find more information? Google isn't helping.
Thanks

Area = (16-sqrt(8**2-5**2)) * 5

70

Why is this picture so stupid? I don't get it, what's the gimmick?

Problem seems wrong. 8^2 - 5^2 ~= 2^2

The given lengths of the sides do not add up.

yup. RIP education

F

so the 5 is wrong

80 square units
My prediction for this thread:
200+ replies arguing over the answer. OP's question never answered.

14x5 equal 70

V for Vendetta?

The 8 is stuck on as a red herring. You're supposed to ignore it.

Area is 80. It's 5*16... good god you people aren't the smartest.

The problem is that the length of the base of the triangle is 7 (= sqrt(8^2 - 5^2)). Since there are two such triangles on the trapezoid, the two bases add up to 14, leaving 2 (= 16 - 14) as the middle part of the trapezoid base. But that is contradictory since the top of the trapezoid is 12 and 12 =/= 2.

5x2 accounts for both triangles m8

70

wrong, 70

Yeah Google doesn't show nothing because it's from a frigging movie. You literally remembered the plot to a movie.

you have to be a fool, you can do this in your head without any fancy math whatsoever

How

You have confounding facts. Either the 8 is wrong, the 5, or the 16. Unless you make an assumption that one of the provided lengths is incorrect you cannot solve the problem.

See I was just gonna say ignore it because you still figured out it was a 2 and you can use the base times height times 1/2 formula to find the area of both triangles then find the area of the center and add them all up. Just because it’s an abstract situation doesn’t mean it’s impossible to solve.

Wtf
You cannot construct the shape in pic related

Whoops, right you are.

16-12 for the missing length of both triangles, take half away as you disregard the second triangle leaving 2.
2x5, the area of both triangles combined
5x12 for the area of the square
add those two products for 70

5*14 = 70

Triangle inequality

yeah op, sorry, your question isn't going to be answered. as for the problem,
0.5 * 5 * (12 + 16) = 70
this is putting aside the fact that the trapezoid is impossible to construct with those dimensions. sqrt (8^2 - 5^2) = sqrt (39). 12 + 2*sqrt (39) =/= 16.

>The 8 is stuck on as a red herring. You're supposed to ignore it.
And this is how the department of education brainwashes kids to ignore facts and just believe and do whatever authority tells you to.

The formula to find it is 1/2 * (12 + 16) * 5 = 70, but the object as shown with 8 would be impossible. You're supposed to ignore the 8 and just perform the calculation you've been trained to do. But why would you teach kids to ignore an evident property? If you include it in the analysis the object is impossible, that can't be an 8, so why is it there at all? Someone had to think to add it. You want to know why kids are so fucking stupid, it is because of shit like this. Even if they can do some things technically correct they are still stupid as fuck because they've been trained to ignore properties and just do as they've been told.

The math problem is made to force you to solve area problem is the most efficient possible way by making the 5 on the left unequal to the missing 4 from the 12 on the top that would make it 16. This one must multiply 5*16 as if it were a rectangle and with that you're also counting up are in a triangle that exists equivalently (or so you assume) on the other side. The answer they're looking for is 80.

no worries, its just a rectangle with a sliver cut out

You're counting each triangle as a rectangle. 2 right triangles with X=5,Y=2 would be 1 rectangle with area (5*2).
Total area is 70.

checked
*sigh*

Because you haven't taken your own logic to the next step: they are intentionally confounding reality. It isn't about them accepting opinions or disregarding evidence: they are teaching them reality is wrong.

I blame the usual suspects

>Unless you make an assumption that one of the provided facts is incorrect you cannot solve the problem.
really makes my nuts wet

You can't do 16-12 for the missing length idiot. Do 8^2-5^2=x and take the square root to find a missing length. It's not equal to 5 so therefore your method of solving is incorrect. The problem is purposely made like this so you have to solve it the most efficient way (5*16 which is 80)

you win the most

>people still keeps arguing over a fucking typo in a shitty book after years

you cant be serious...

If the bottom of the shape is actually of length 16, then the following is true for the rest of the measurements:
Left side: 8.5
Top: 8
Right Side: 8
Height: 7

a^2 + b^2 = c^2
2^2 + b^2 = 8^2
4 + b^2 = 64
b^2 = 16
b=4
That 5 should be a 4. Public schooling needs to go away.

Right that's what I was getting at. They're practically pushing the classic 2 + 2 = 5 on kids. They teach you to not analyze something you see, that if you include it or even state that the object is impossible then you are wrong.

WHAT THE FUCK ITS GODAMN EASY, 16 IS THE BOTTOM, THEN YOU GOTTA SEE THAT THE TOP IS 12 SO THERE IS 2 ON EITHER SIDE OF THE BOTTOM 12 MAKING A SQUARE OF THE DEMENSIONS 14X5 =70

IGNORE EVERYTHING ELSE

- MATH PROF.

No it wasn't a typo, these sorts of problems are very common where you are given extra information that you are supposed to ignore but would make the object impossible if you included it in an analysis.

you sure as shit can. How do you pay for things at the store?

Either the 8 or the 5 must be incorrect. If you assume the 8 is incorrect then ya the answer is 70. But if you assume the 5 is incorrect then the height is like the square root of 60.

why do people keep saying 80 tho

I am talking about real life, not V For Vendetta

Why do you guys think the answer is 70? There is no indication that that dotted line is 90 degrees from 16 line. Also it is impossible for 5 to be right angle to 16 because square root of 39 is more than 4 cm. All of you are retarded.

Its not a fucking square holy shit you dumb american

because when you do this in your head it is easy to add another 10 units for the other triangle when 10 is actually the area of both triangles. It's a bunch of upset millenials who can't come to grips with mental math and extra information.

Cos (5/8) = 1
2[(5*1) /2] = 5
12*5 = 60
60+5 = 65

65

Probably doing 16-12 but not splitting the 4 onto both missing pieaces.

its a mental math exercise for younger people, not a chalkboard problem for wannabe matt damons

Sounds like something out of a comic book. Not sure that it didn't happen here and there, but not likely widespread if it did.

The triangles on either end can be relocated to create a rectangle with a length of (16+12)÷2=14 meaning the short leg of each triangle is 2. If we assume the 5 is correct, the area is 70. If the 8 is correct, the area is 108.5. Both cannot be correct.

...

Dude we learn about that kind of geometry problem when we are 14 years old. Our teacher won't give us such unsolvable questions. The children will rip the teacher apart for giving impossible situation in an exam.

Yeah, if 5 and 8 are right opposite then sine is 6.24. But that is greater than 16 negative 12 divided by 2 which is 2. So 8 would have to really be 5.38. The correct answer is that Common Core is wrong.

yeah you safely ignore the 8 because of this. no context other than solve for area is given and everyone can't seem to visualize this. It's a teen math problem. You work with the information given and discard the unneeded. This has been taught since I was in primary school. I was a TAG student.

As you can see, the 12 and the 16 are not parallel anymore hence 70 is not the answer. The question in the OP has a lot of problem. 5 and 16 is not shown to be right angle to each other, and 12 and 16 has no indication mark that they are parallel.

because 99% of the time these stupid images say "images not to scale" in the bottom corner

Yea the original question does not specify that the 12 and 16 are parallel. It's probably ok to assume that the 5 is at a right angle to the 16 because otherwise you no longer have a unique solution.

/thread

80
Area of inner rectangle = 12* 5 = 60
Area of right angle triangle = 5 *((16-12)/2) / 2 = 10
Total area = 60 + 10 + 10 = 80

I think it was in italy or in a hollywood movie

no, its not that kind of problem, you are pulling context where there isnt any, you solve for area and thats it. You discard what you dont need to solve, for instance the apparent hypotenuse of what is surely a right triangle is only labeled on one side to indicate symmetry. Thats why you only need the height and the length of the top and bottom to solve for area. We are doomed if im the only one that can see this. Our teachers spent maybe a single day on 'extra information' as it was called.

You are doomed if you can't see that my answer is the only possible correct one:

There's two possible answers with no context as to which information might is relevant and which may be safely discarded. It intentionally confuses the reality of mathematics. To what end?

This. The teacher fucked up. Probably wasn't paying too much attention. It's really not a big deal. One acceptable answer should be 70, another, even better answer is to ignore the 5 altogether, use the symmetry to conclude that instead of 5 it should be sqrt(60) on that dotted line (assuming line meets at right angles), and get answer of 14*sqrt(60) units squared.

It's okay in education to give an "unsolvable" question, and encourage the brighter students to think outside the box.

you call that a shitpost

Explain how I am wrong

Protip: you are a fag

You can't have a right triangle with sides of length 2,5,8 you twat

If 80 from 5*16
then 5 is right with 16
and so would 16 - 12 be right angled.
Also 16 is the full length of the line, not just from the bisection with the 5. so it would have to be 5 times 14. or 5 times (12 plus the pytho of 5 and 8).

You're all really stupid. This is good for me!
This is a type of trapezoid.

You might think that you could find the area of the 'triangles' and the square then add them together. I guess you could!

It's much easier to get (12+16/2)*8 = 112 cubic units.

...

A=c*(a+b)/2
A=5*(12+16)/2
A=5*28/2
A=5*14
A=70

to solve for area, i'll say it once more, this problem is given to TEENAGERS to get them to recognize and remove uneeded information after they have been instructed how, so a series of examples are given, the OP being the example. You trim the 8, thats the only lesson you are supposed to take away. You arent supposed to sit down and think about wether or not the triangle is a right one or not, it would be labeled if it were important enough. I literally cannot overstate how much you are overthinking a simple problem.

wat did tehy meen by tihs

The question is obviously for the purpose of understanding basic area calculation.
Putting all that extra effort is not the purpose of the problem. You're being an autist.

You obviously weren't vaccinated
So you don't have autism
So you don't have to do your math on plausible objects

That or you grew up with common core so you're retarded enough to accept how ridiculous it is.

whoops

Why not just use the formula?

0.5h(a+b)

0.5*5*(12+16)= 70.

>Common Core is wrong

Get a load of this retard. Common Core will turn the children into litteraly human calculators.
You're going to be outsmarted so hard.

>pic related

Wow, you're all really, really dumb.
The 16 on the bottom is describing the entire length of the bottom of the object. Not just the length beginning from the dotted line.
The 12 on top is parallel to the 16 on the bottom. This is a totally possible shape, it's called a trapezoid.
You see this type of labeling all the time in mathematics. But it's the way it is.

It’s clearly non-Euclidean geometry, fucktard.

But would the retarded teacher accept that answer?

>You're being an autist.
Piss off. His solution is probably the best given the problem at hand.

Er, I got the height mixed up. Just swap out 8 with 5 and 112 with 70. The main point I'm trying to make is that the thing isn't labelled strangely, you've just misunderstood. It happens.

>all these brainlets not knowing a right triangle can't have sides of 8, 5, and 2

>This is a totally possible shape, it's called a trapezoid.
>You see this type of labeling all the time in mathematics. But it's the way it is.
What's a shape? I don't understand your answer can you explain again?

I feel you, dude

its a lesson in extra information, you ditch the 8 and solve the rest mentally in a half second. I remember this day in school, almost all of the kids failed even the 'bright' ones.

Maybe my answer is correct. If the exercise was like pic related, then my answer would be false.

...

m=(16+12)/2

14*5

I'm pretty dumb, I fucked it up myself, but I'm just glad I'm able to see that it's not some mystery shape or something, the original intent of the OP image is just because whoever made it is truly, truly a spiteful idiot.

Using the pythagorean theorem for a right triangle, if we look at the trapezoid as a rectangle with two triangles, we get:

8^2 = 2^2 + 5^2

but this is fucking wrong, because 64 isn't 29

the shape shown can't exist

but this shape is impossible

the top cant be 12

the small piece would be 6.3 or so, now compare the top and bottom with the known measurements

12 = 16 - 6.3 - 6.3

impossible

I'm asking what determines which set of information is irrelevant. Why is the 8 and not the 5 disregarded?