# Chapter 5 Blocks

## 5.1 Equations

Here is an equation.

$\begin{equation} f\left(k\right) = \binom{n}{k} p^k\left(1-p\right)^{n-k} \tag{5.1} \end{equation}$

You may refer to using \@ref(eq:binom), like see Equation (5.1).

## 5.2 Theorems and proofs

Labeled theorems can be referenced in text using \@ref(thm:tri), for example, check out this smart theorem 5.1.

Theorem 5.1 For a right triangle, if $$c$$ denotes the length of the hypotenuse and $$a$$ and $$b$$ denote the lengths of the other two sides, we have $a^2 + b^2 = c^2$

## 5.3 Callout blocks

The bs4_book theme also includes special callout blocks, like this .rmdnote.

You can use markdown inside a block.

head(beaver1, n = 5)
#>   day time  temp activ
#> 1 346  840 36.33     0
#> 2 346  850 36.34     0
#> 3 346  900 36.35     0
#> 4 346  910 36.42     0
#> 5 346  920 36.55     0

It is up to the user to define the appearance of these blocks for LaTeX output.

You may also use: .rmdcaution, .rmdimportant, .rmdtip, or .rmdwarning as the block name.

The R Markdown Cookbook provides more help on how to use custom blocks to design your own callouts: https://bookdown.org/yihui/rmarkdown-cookbook/custom-blocks.html