Steven has a counter that is yellow on one side and blue on the other. the counter is shown below: steven flips this counter 22 times. what is the probability that the 23rd flip will result in the counter landing on yellow side up?

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

correct answers below: