Answer:
Step-by-step explanation:

First and third options are correct
Answer:
B) y = x + 2
Step-by-step explanation:
Coordinates of point C =
Coordinates of point D=
To find the equation of segment CD
Formula : 
Substitute the values in the formula :

y-12=x-6
y=x+6
When two lines are perpendicular to each other the product of their slopes is -1
Let the slope of perpendicular line be x
So, -1 \times x = -1
So, x =1
General equation : y = mx+c
So, Option B has slope = 1
So,the equation of the line that's a perpendicular bisector of the segment connecting C (6, –12) and D (10, –8) is y = x + 2
The sum of the angles in a heptagon is 900°, so we would add the real numbers that we have here:
121°+139°+125°+126°+158°+120°=789°
x would equal the remaining value:
x=900-789
x=111°
Answer:
0.3 cm
Step-by-step explanation:
1 cm = 10 mm
1) Using proportion:
1 cm ----- 10 mm
x cm ----- 3 mm
x = 1 cm * 3 mm/10 mm = 0.3 cm
2) 3 mm * 1cm/10mm = 0.3 cm