What is the perimeter of a 81cm^2 area?

Expresa commuter train leaves downtown sation and travels at a average speed of 55 miles per hour towards the north side sation, which is 50miles away. thirty minutes later, express commuter train #7 leaves north side and travels at a average speed of 35miles per hour towards downtown sation. at the moment the two trains pass each other, how far(in miles) is train #12 from the downtown sation and how long(in minutes) has the #12 train been traveling

Drag each tile into the correct box. not all tiles will be used. find the tables with unit rates greater than the unit rate in the graph. then tenge these tables in order from least to greatest unit rate

The anwser cause i do not understand just plez