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
No, you should completely ignore the bottom half of the center line. You end up with a shape with four turns. Those four internal angles always add to 360.
He is saying your shape might have 5 turns instead of 4 if the bottom line is not actually a line. Though if that was the case, the problem would not be solvable, so I doubt it.
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
Nice one, forgot this was an option too. You are missing a set of brackets though ;)
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
No, you should completely ignore the bottom half of the center line. You end up with a shape with four turns. Those four internal angles always add to 360.
He is saying your shape might have 5 turns instead of 4 if the bottom line is not actually a line. Though if that was the case, the problem would not be solvable, so I doubt it.