What number increased by 8% of it self is 1944

1800

Step-by-step explanation:

Basically you want to know how much a number is so you have to add 100 percent of it, which is 1.00, plus the 8 percent, which is 0.08, giving you 1.08. then you divide 1944 by 1.08 to get 1800.

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.