I my maths assignment is due tomorrow, HELP Please!?

Question

Help! Im trying to find out the perimeter of a non right angled triangle, and its giving me a negative number, Problem-> 1/2*38.75²*39.15²sin50

Answer 1

I'm not sure what your question is?

That formula looks a bit like the formula used in the Cosine Rule to find the length of a third side, when you know the length of two sides and the angle between them. But the cosine rule actually looks like this:

c² = a² + b² - 2*a*b*cos θ

where θ is the angle opposite side c (between sides a & b)

Perhaps you can post the whole question as written so that we can better understand what you are asking.