5.3.4 Practice: Modeling: Finding Parallelograms Please help (I am giving 100 points and will make brainiest)

I have attached the questions on a PDF down below

If 1 km = 0.621 miles, how many miles are in a centimeter

How do i start to solve? would appreciate a walk-thru! a bird sitting 16ft above the ground in an apple tree dislodges an apple. after how many seconds does the apple land on the ground? (assuming that no branches will interfere with it's fall)

Use the formulas a = x 2 – y 2, b = 2xy, c = x 2 + y 2 to answer this question. one leg of a right triangle has length 11 and all sides are whole numbers. find the lengths of the other two sides. the other leg = a0 and the hypotenuse = a1