Write Python code using the turtle module to draw a square and a regular pentagon.

Here are the instructions for the two shapes:

1) Square (side length 10)
To draw a square, the turtle needs to move forward for each side and turn an exterior angle of $90^\circ$ at each corner. Since there are 4 sides, this sequence is repeated 4 times.

$$\text{Repeat the following 4 times:} \\ \text{fd 10} \\ \text{rt 90}$$

2) Regular Pentagon
To draw a regular pentagon, the turtle needs to move forward for each of its 5 equal sides and turn an exterior angle. The exterior angle for a regular pentagon is $\frac{360^\circ}{5} = 72^\circ$. Assuming a side length of 's' (e.g., 50 steps), the sequence is repeated 5 times.

$$\text{Repeat the following 5 times:} \\ \text{fd [side length]} \\ \text{rt 72}$$

(You can replace [side length] with a specific number like 50 or 100.)