Is -51/5 rational or irational

What is the length of an with endpoints a 3,2 and b 8,14

After applying the composition r0.90 ry to rs what are the coordinates of r' and s'? a.r'(–3, 1),  s'(–3, 5)b.r'(–1, 3),  s'(–5, 3)c.r'(1, 3),  s'(5, 3)d.r'(5, 3),  s'(1, 3)

What are the coordinates of the midpoint of ab? ,1/2) /2,-1) ,-3/2) /2,-2)