Linda purchased a prepaid phone card for 30. Long distance calls cost 19 cents a minute using this card. Linda used her card only once to make a long distance call. If the remaining credit on her card is 23.73 , how many minutes did her call last?

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.

michael scott & dwight schrute

step-by-step explanation:

lazy scranton music video