Answer:
10 units
Step-by-step explanation:
to find the distance between two points you will need to use the distance formula:

the x1 refers to the x coordinate in the first bracket, the x2 refers to the x coordinate in the second bracket, etc.
insert the coordinates into the equation:

a double negative equals a positive
insert this equation into your calculator:
= 10
∴ the distance between the points (1,1) and (7,-7) are 10 units
I hope this was helpful :-)
The answer is 35/18 because you flip 3/7 and multiply it by 5/6
To find the the amount of how much the stadium is cleaned you can
In a right triangle, the square of the largest side is equal to the sum of the squares of the smaller sides, so if you plug the sides in to that equation, you should get zero if those sides form a right triangle.
B is the only option where this is true, so I believe set B defines a right triangle.