Answer: 29 ft
Explanation:
Based on the description we are given. we know that we can form a right triangle, where 20 and 21 are the legs. The length from the girl to the bike would be the hypotenuse. To do this, we need to use the Pythagorean Theorem, which is
, where a and b are legs, and c is hypotenuse. We can go ahead and plug them in.
[exponent]
[add]
[square root both sides]

Therefore, the distance from the girl to the bike is 29 ft.