Imagine right triangle PHF, where P - park, H - home and F - football field, then PH, PF are legs and HF is hypotenuse . Denote point L to be library. You know that point L lies on the segment FH and FL=8, LH=2. Also you know that PL is an altitude to the hypotenuse.
Use the property of altitude drawn from the vertex of right angle to the hypotenuse (the length of the altitude is geometrical mean between legs' projections onto hypotenuse):
mi.
This means that the distance between park and libriry is 4 miles.
Consider right triangle PLF ( angle L is right angle and PF - hypotenuse). By the Pythagorean theorem,
mi. The distance between park and football field is
miles.
Answer: the distance between park and libriry is 4 miles and the distance between park and football field is miles.