1. B C(The slopes of AC and BC are opposite reciprocals, making them perpendicular, making the triangle a right triangle, and AC and BC have the same lengths)
2. AC = BC = sqrt(2^2 + 4^2) = 2sqrt5
You multiply them together, then divide by 2. You get 20/2 = 10
3. DE = FG = sqrt(3^2 + 1^2) = sqrt10
EF = DG = sqrt(4^2 + 1^2) = sqrt17
Add sqrt10 and sqrt17 together, then multiply by 2, and you get... D
4. A, D ( The image is a parallelogram, making the sides equal lengths and parallel (They technically are proportional, because they are equal, but IDK if you should put proportional too.))
5. D (There are 2 pairs of congruent sides, which are opposite each other, which is the definition of a parallelogram.)