Hi, I need to find the obtuse angle between the lines l and m
I don't know how I am supposed to do it, my professor hasn't told me about it.
You have to use parametrics to solve the issue.



Can anybody help me solve this issue? Or just give me a hint on how to solve it?

Vector (-1 ; 2) leads line l,
vector (0 ; 6) leads line m.

Are you aware of the dot product between two planar vectors, and about its meaning ?

Yes, I'm aware about how to find the intersection between the two lines, but I have almost no idea about how to find the angle the two lines make up :S

a • b = |a||b|*cos♧

Thank you!