If i have the squuare root of 75000 could i divide that answer by 3 to get the answer to the square of 25000?

Which of the following of the following sets of side lengths could not form a triangle?

The tile along the edge of a triangular community pool needs to be replaced? ?

Two trains leave stations 546 miles apart at the same time and travel toward each other. one train travels at 95 miles per hour while the other travels at 115 miles per hour l. how long will it take for the two trains to meet