If 8 out of 20 students in a class are boys, what percent of the class is made up of girls?

60%

Step-by-step explanation:

8 is 40% of 20, therefore the girls would make up 60% percent of the class.

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.

hello,

as   long as they add up to 180 its correct.