Answer:
A row of 56 half dollars will be 1736mm long
Step-by-step explanation:
Given:
The diameter of half dollar = 31mm
Solution:
If we put two half dollar in a row then the row will become
![2*31=62mm](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2gkd50pwkssn2olucjyh1momp6djk0scjz.png)
But we put another two half dollars in a row then row will be long and becomes=
![4*31=124mm](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gf6cgjvdc2ed3grkek8vctwcrgc1ntpn7v.png)
Similarly
If we put 56 dollars in a row then row will be long and becomes =
= 1736mm