Answer:
16
Step-by-step explanation:
DE is the vertical line x=1. It extends between y=2 and y=7, a distance of 5 units.
EF is the horizontal line y=7. It extends from x=1 to x=4, a distance of 3 units.
Then the perimeter of half the rectangle is 5+3 = 8 units.
The perimeter of the rectangle is 2·8 = 16 units.
The answer is -2.5. this is how you work it out.
21.4 + (-23.9) = -5/2 = -2.5
Since the angle are both 45 degrees, then you know that both legs are equal=12.
so to find the hypotenuse, you use the pythagorean theorem:
12^2+12^2= c^2
144+144=c^2
288=c^2
square root(144) x square root (2)=c
12 square root 2 is the answer, so D.