135° for anyone wondering.
correct, just commenting 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
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).
For context: it used to be 675° a few years back so the math checks out.
that's not how global warming works
I got 125.
180-(90-35)=x 180-55=x 125=x
It isn't 90 degrees because the image is misleading. 60+40+y=180. y=80
I hated pictures like this in school. The numbers are just slapped on an inaccurate image and somehow they expect people to ignore the obvious right triangles and just focus on the math part of it.
Fun fact: In Turkey's university admittance exam, all angles have to be absolutely accurate, and measurements have to be scaled down perfectly to the visible shape in a geometry question.
all angles have to be absolutely accurate
To what tolerance, though? Writing math exams has now become an engineering problem.
If it was to scale you could just use a protractor and skip the whole math part, which is the entire part of the lesson…
I don't see that as a downside as long as these two questions are also included.
How many degrees make up the inner angles of a triangle?
How many degrees make up one side of a straight line?
Then they could use decimals so it's unlikely to get it right without calculating, 60.17°, 40.29°, 35.43°
If the student eventually does geometry for money, they'll discover that customer CAD files invariably have some bizarre error like this.
I was scared I forgot basic trig stuff.
It's even easier than going the triangle route.
A four-corner shape always has 360° internally.
So the internal angle of corner X is 360-(60+40+35).
The exterior angle therefore is 360-360-(60+40+35) = 60+40+35 = 135
That's based on the assumption that the two angles in the middle add up to 180, which can't be assumed by inspection alone as demonstrated by the visibly square 80° angle
Nice one, forgot this was an option too. You are missing a set of brackets though ;)
I love that every comment focus on the math puzzle. Since the other stuff is clearly uninteresting.
