Which equation can be used to find the answer?

a fence with four sections has a perimeter of 43 ft. three of the sections have lengths of 8 ft, 12 ft, and 11 ft. what is the length of the fourth section?

x – 8 + 12 +11 = 43

x = 43 + 8 + 12 + 11

x – 43 = 8 + 12 –11

x + 8 + 12 + 11 = 43

x + 8 + 12 + 11 = 43

Step-by-step explanation:

this one is the one to find x

basically subtract all those numbers from 43 to get 12 ft.

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.

b. astronomers