Cual es el nombre del lado mas largo de un triángulo rectángulo

The vector matrix [2/7] is dilated by a favor of 1.5 and then reflected across the x axis. if the resulting matrix is [a/b] then a= and b=

3.4a=57.8 what is the the value of a

In the triangle rst, rs = 65 and st = 60. which equation could be used to find the value of angle s?