Biased, because there is only survey of one group of people (one grade, one class). The sample (the class) is too small compared to the population (assuming it’s an average school size). You will end up with less than 1 percent of the population size thus the survey is not reliable information.
I believe it to be 1 over 3 as 1 as the numerator and 3 as the denominator
The two horizontal lines are parallel.
This makes the 80 degree angle and the angle ox x and 20 degrees are alternate interior angles and are the same.
This means x + 20 needs to equal 80.
X = 80-20 = 60 degrees.
The answer is a vertex. Corners of any shape are vertexes