Step-by-step explanation:
1) if (0;0) if point A, (1;2) is point B; (-1;-2) is C, (2;1) is D, then
2) the vector AB is (1;2); vector AC is (-1;-2) and vector AD is (2;1), then
3) the length of AB, AC and AD are:



4) if the lengths above are equal, then it means that (0, 0) is equidistant from (1, 2), (-1, -2) and (2, 1).
Answer:
m+n=140
Step-by-step explanation:
So the angles in a triangle always add up to 180. We already know that the first angle in the triangle is 40 degrees because it's shown in the angle below the triangle. So we have 140 degrees left since 40 is taken up. That eans m+n=140
Kevan is 8
katie is 14
Melanie is 16
I think this is the answer.