AB and ED are parallel, which we can see from vertically opposite angles, so a must be 70.
>>143509056
How do you know they are parallel ? You don't know either alpha or EDB right ?
>>143509056
Hello again.
>parallel
Elaborate. That thing is not to scale. Even if it were, open it on paint and prolong the AB and ED.
They'll meet, and they're therefore not parallel.
>>143509056
Wait, something is off about this. The smaller triangle where the base is A - B, the missing angle should be 50 degrees, but the angle is obtuse.
>>143509056
I am trying to solve this, and I need to ask : when they say "no trigonometry", how much am I not allowed to use ?
Do I know that the sum of all angles in a triangle is 180° ?
Angle CDE is 120 and angle BDA is 40.
That would imply line CDA is 160, which means it isn't a straight line. Triangle ABC isn't even a triangle.
Mod plesase do the job
>>143509056
>drawing is to scale
>50 degree angle is obtuse
>remembering how to do trigonometry
We're not all at school anymore.
>>143510306
>>143509796
doesn't need to be to scale, the entire point is to solve it using angle theorems
>>143510121
CDE is 140.
>>143510449
*I mean CBD
>>143510484
I mean CDB. Thank god for sage
>>143510449
You're right.
Math is hard
>>143510121
>CDE is 120
Where did you get that from?
You're also missing EDB in the calculation.
It's been said countless times, but it's impossible to get a definite solution with those values alone without using trigonometry.
You can at best come up with a range of values.
>>143509056
Impossible. That is not a 50 degree angle. These 'objects' do not form triangles with 180 degrees therefore no other angles can be inferred.
I guess you could use non euclidean geometry but then how do you determine the plane?
>>143510598
The crap drawing doesn't change the fact that it's a Euclidean triangle.
>>143510598
the entire point of these problems is to make the question impossible to solve with a protractor
Learn some basic geometry before trying to solve things via non-euclidean methods
>>143510598
Have you considered that it's not to scale? BAC is clearly closer to 60 degrees, while it's supposed to be 80.
People who expect a diagram to be drawn to scale can't have done much math
People who think there might not be a solution suck at applying basic sanity checks
>>143510775
What did you use to draw that?
>>143510851
My dick.
>>143510851
https://www.geogebra.org/geometry
>>143510775
It not being to scale just fucks with my head, since I always do things visually in my head to gain a sense of space. Since this drawing is already there, I'm trying to wrap my head around it with the appropriate angles, but it's obviously not drawn to scale.
>>143509056
Draw a line from D to a point on BC, to be called F, such that DF is parallel to AB.
Welcome to solution town, population you.
>>143510775
How do you get those without using trig. It's been about 20 years since my highschool geometry.
>>143510040
Yes, you probably can't use trigonometric functions and the like, the sum of the angles thing is basic geometry.
>>143509056
>AB and ED are parallel
>which we can see from vertically opposite angles
That's not how vertically opposite angles work. All that proves is that the third angle in the A-(angle next to alpha)-B angle and the E-(angle next to alpha)-D angles are the same.
You'd know that they're not parallel as soon as you looked at the angles next to the BD and AE lines. Because one is 70/10 and the other 60/20, ED should be tilted in comparison to AB. As a matter of fact, even in this poorly drawn diagram, ED is slightly tilted in comparison to AB. It's more obvious in >>143510775 though.
Try again OP.
I don't like the explanations here. I will do better.
Can we determine any angle in CDE?
>>143513424
nevermind that
Ah. it's impossible. Now I feel a bit silly trying to do this.
>>143511162
It's called the Hardest Easy Geometry Problem. Completely possible using just basic geometry principles. Drawing it to scale actually helps a ton to visualize what steps you have to take to solve it
>>143514068
Is it actually possible? I don't see how you can find alpha without solving the triangle CED but how to find either angle CED or CDE isn't something I find how to do.
>>143514183
Look it up if you want, I won't spoil it for the people that want to try to solve it.I had to look it up to solve it
>>143513929
It's not, a=20
For all you morans out there pining for the complete solution
...https://www.duckware.com/tech/worldshardesteasygeometryproblem.html...
