How can i tell if the slope on a graph is positive or negative?

When are triangles considered similar? a. corresponding angles are equal andcorresponding sides are proportionalb. corresponding angles are proportional andcorresponding sides are equalc. corresponding angles are equal orcorresponding sides are proportionald. corresponding angles are proportional orcorresponding sides are equal select the best answer from the choices providedmark this and retumsave and exitnext

Me. i can't figure out this question. give an explanation too. .

Lines a and b are parallel. what is the value of x? -5 -10 -35 -55