PLEASE HELP!!!what is the length of segment SR? units

According to the attachment at point it makes the angle of 90° with both triangles, so;
SR = SQ
2x + 8 = 8x - 4
and if we find the value of x, we will find the value of  line segment SR
8x -2x = 8+4
6x = 12
x = 12/6
x = 2
now put the value of x in SR = 2x + 8 = 2(2) + 8 = 4 + 8 = 12
SR = 12