All of them could be as A would be an equilateral B,C,D would be irregular triangles and 3 would be an Isosceles triangle but if you had to go with one it would be A
Work shown above! Answer is A = (πD^2)/4. d = diameter
Hope this is what you were looking for!
Ok I’m im not sure you can ask someone else sorry
Additive inverses combine to get 0. So, k is -1.4. The sum is 0. Hopefully that will help.