How do I solve this problem? Thank you.

Pete is making decorations for a dinner party. the instructions tell him to use 9 flowers for a medium-sized decoration. complete each statement to adjust the flowers for different-sized decorations based on these instructions.

Given: △acm, m∠c=90°, cp ⊥ am , ac: cm=3: 4, mp-ap=1. find am.

If t8 = 4 and t12 = −2, find the first three terms of the arithmetic sequence.