√- 81 doesn't result in a rational number because you can't get a negative from squaring any number. Instead you get a number with an imaginary number.
13 - √- 81 = 13 - 9i
Answer:
Circumference of circle= 37.68 units
Circumference of sector= 6.28 units
Step-by-step explanation:
The given figure is a circle with given radius OB= 6 units.
The circumference of a circle is the total length of its boundary.
For the complete circle its circumference can be calculated by;
Circumference= 
units
For the circumference of the Sector with 60° in the figure, the circumference can be calculate by:
units
So, the circumference of the full circle is 37.68 units and the circumference of the sector is 6.28 units.

The constant of proportionality,m, is 3 (option B)
11/3 is bigger 1.27 because when you do 11/3 you get 3.66666666666666666667 which is clearly bigger than 1.27 so like I said 11/3 is bigger than 1.27.