There are three types of structures ("structs") that can be created using the
`struct` keyword:
-* Tuple structs, which are, basically, named tuples.
-* The classic [C structs][c_struct]
+* Tuple structs, which are, basically, named tuples. The classic [C structs][c_struct]
* Unit structs, which are field-less, are useful for generics.
```rust,editable
### Activity
-1. Add a function `rect_area` which calculates the area of a rectangle (try
+1. Add a function `rect_area` which calculates the area of a `Rectangle` (try
using nested destructuring).
2. Add a function `square` which takes a `Point` and a `f32` as arguments, and
returns a `Rectangle` with its lower left corner on the point, and a width and