If I remember correctly judging from the 30 in the top left all you would have to is subtract 180 which is the angle of a straight line and subtract it from the 30 and it would be 150
Solution:
Vertical angles are a pair of opposite angles formed by intersecting lines. re vertical angles. Vertical angles are always congruent.
These two angles (140° and 40°) are Supplementary Angles because they add up to 180°:
Notice that together they make a straight angle.
Hence,
From the image
The following pairs form vertical angles

Hence,
One pair of the vertical angles is ∠1 and ∠3
Part B:
Two angles are said to be supplementary when they ad together to give 180°
Hence,
From the image,
The following pairs are supplementary angles

Hence,
One pair of supplementary angles is ∠5 and ∠6

<h3>Hope This Helps You </h3>
I'd say around 10%
4 out of 10 = 40%
3 out of the 10 are sold = 30%
1 out of the 3 might be bad = 10%
I may be wrong.
True, and it's called an isosceles right triangle :D