What are the dimensions for a township?

Why do we need to have a standard parallel every $4$ townships $(24$ miles$)$ to the North of the baseline?

What are the dimensions for a full section?

Which sections are fractional sections?

What are the area of the following PLSS descriptions?

a$.$ N $\frac{1}{2}$ of SW $\frac{1}{4}$ of SE $\frac{1}{4}$ of Section $7,$ T $2$ N$,$ R $1$ E$,$ S$.$B$.$M$.$

b$.$ NW $\frac{1}{4}$ of SW $\frac{1}{4}$ of SE $\frac{1}{4}$ of Section $7,$ T $2$ N$,$ R $1$ E$,$ S$.$B$.$M$.$

What are the distances in miles $($N$-$S and E$-$W$)$ from the SW corner of Sec $30,$ T $2$ N$,$ R $1$ E to the NE corner of Sec $14$ T $1$ N$,$ R $2$ E$?$ Assume all sections are full section.

Provided the following figure, what is the area $($in acres$)$ of NW $\frac{1}{4}$ of NW $\frac{1}{4}$ of the section? Show sketch and calculation for credit.

a$.$ Federal Method

b$.1860-1862$