Find the angle at vertex A of the triangle with vertices A(1,0,1), B(-2, 1,3), C (4,2,5). Find the area of the triangle with vertices A (1,4,-1), B(-1,2, 0), C (1,1,3). 3 Find the parametric equation of the line of intersection of the pla x + 2y + x = 1 and 2+ 4y +24=1. Find the curvature of the parametric curve at an arbitrary point. r (t) = , => 0, Find the tangential and normal components of accelerate of the parametric cave r(+) = , s> at += -1, Bonus Problem: Find on each of the lines a x=1+2t x=1 y = 1-t and y=1++ Z== z=2t point such that the two points are the closest possible.