These are top-heavy pyramids. The blue one has $21$ at the apex (top) and the red one has $31$.
In the blue top-heavy pyramid whose base is $4$, $5$ and $7$, $4 + 5 = 9$, so $9$ is placed between and above the $4$ and the $5$.
$5 + 7 = 12$ and $9 + 12 = 21$.
Use the numbers in the box below to make the base of a top-heavy pyramid whose top number is $200$.