---
id: 5d822fd413a79914d39e9901
title: Part 57
challengeType: 0
dashedName: part-57
---
# --description--
Remove the `margin` and `border-top` properties and values from `bb2a` to turn it into a triangle for the top of the building.
# --hints--
test-text
```js
const bb2a = code.match(/\.bb2a\s*{[\s\S]+?[^}]}/g)[0];
assert(!/margin/g.test(bb2a) && !/border-top/g.test(bb2a));
```
# --seed--
## --seed-contents--
```html
freeCodeCamp Skyline Project
```
# --solutions--
```html
freeCodeCamp Skyline Project
```