The following is an expression.
Answer:
With respect to the reference angle, one leg is the adjacent leg, or the leg right next to the reference angle; and the other leg is the opposite leg, or the leg on the opposite side of the triangle. If two triangles are similar, the ratios of corresponding sides are equal.
It's easier to write if you convert 1/4 into 0.25.

Then you use algebra to find that he ran the mile in 6.4 minutes.