What number should Rihanna use for the height of the parallelogram if she uses 28 inches for the base

Use the formula r = d/t. Your rate is 24 miles divided by 2 hours, so: r = 24 miles ÷ 2 hours = 12 miles per hour. Now let's say you rode your bike at a rate of 10 miles per hour for 4 hours.

B) Plugging in the given numbers, solve r = 760,320 yards / 2 hours = 380,160 yd/hr.

Looking up the conversion from yards to miles, 1 yard = (1/1760) miles. Then multiply by our answer in (B) by that ratio => (380,160 yd/hr)*(1 mile/1760 yd) = 216 mi/hr

Use miles in this scenario because of the number of significant digits (yards would require a number in the hundred-thousands).