The area of this rectangle is 5x? What does the coefficient 5 mean in terms of the problem?
width x
length 5x
A. The length is 5 times the width.
B. The total area of the square is 5.
C. The length is 5.
Ma
D. The width is 5 times the length.

A. The length is 5 times the width

Step-by-step explanation:

When a number is next to a variable, like 5x, it means you multiply the number and letter. So "5x" is really saying 5 · x

Since width is equal to x, the length is 5 times the width.

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.