Anonymous asked:How would you answer question 16 under the angles and non-right triangles section?
That one’s tricky, no? The key is to notice that all the marked angles are clustered on straight lines. There are 4 sets of marked angles that add to 180º.
You could also plug in numbers and try to get all the triangles and straight lines to add up to 180º, but in this case I wouldn’t recommend it. :)