Pls help me, brain list and a thanks

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

Hi, can anyone show me how to do this problem? 100 points for this. in advance

What is the 17th term in the arithmetic sequence in which a6 is 101 and a9 is 83