C=4,2 kj/kg
C=2 C=2,14

for finding the midpoint of any given 2 pair of points simply add the respective x coordinates with other x coordinate and the y coordinate with other y coordinate and divide them by 2

in your question it will be :

(3+1)/2 for the x coordinate of mid point i.e 2

[8+(-4)]/2 for the y coordinate of midpoint i.e 2

so coordinates of mid point of points (3,8) and (1,-4) will be (2,2)

your question is incomplete, write all the numbers in the sequence that it tells you.  

step-by-step explanation:

the answer is c: divide the arc's degree measure by 360°, then multiply by the circumference of the circle.