I want to rotate a triangle created with CSS from the top-left or top-right sides. For example, in the attached image, there are two cases of triangle rotation. In the first case, the triangle is rotated from the top-left, and in the second case, it’s rotated from the top-right. Is there a way to implement these rotations simply using CSS?

i try to show sample in this images:

The first triangle is rotated inward from the top-left.
The second triangle is rotated inward from the top-right.
I tried using transform: rotate(), and it’s work fine for up to down or backward , but I’m not sure how to change the rotation point to the top-left or top-right.
try to show this rotate with transition .

Any guidance or code samples to help me achieve this would be greatly appreciated!