Pam is looking for a new car. she has test-driven two cars but can only purchase one. the probability that she will purchase car a is 0.46, and the probability that she will purchase car b is 0.34. what is the probability that she will not purchase either car a or car b?

0.12
0.40
0.20
0.80

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.