Can somebody please help me with these?

What is the length of the unknown leg in the right triangle ?

The diagonals of a quadrilaretral intersect at (-1,4). one of the sides of the quadrilateral is bounded by (2,7) and (-3,5) determine the coordinates of the other side in order for the quadrilaretral to be a square.

On the first of each month sasha runs a 5k race she keeps track of her times to track her progress her time in minutes is recorded in the table