Question

how do you find the perimeter of a triangle that doesn't have a 90 degree angle

Answer 1

You have to use the law of sines. This shows a relation between edges and their opposing angles. Instead of me writing it out here it might be easier for you to google it for diagrams and examples. Hope that helps.

Answer 2

If not that then the law of cosines. But this depends on the information you have about the triangle. Again you will have to google it.