80% bc 20/25 equals 4/5 and 4/5 equals x/100 and when you do that math it equals 80%
<t =33 since triangle RUT is isosceles (RU = TU)
<r + <u + <t = 180 triangle = 180
33 + <u + 33 = 180
66 + <u = 180
< u =114
<rus = < sut from the diagram
<rus + <sut = <u
x + x = 114
2x = 114
divide by 2
x = 57
Rory walked 2/4 of a mile more than Louise.