2) Let A be the triangle with vertices the points P=(3, 1,-1). Q=(2,0, 3) and R=(1,1,1). Determine whether A is a right angle triangle. If it is not, explain with reason, why? 3) Let = < 0,1,1>, V = < 2,2,0> and < -1,1,0> be three vectors in standard form. (a) Determine which two vectors form a right angle triangle? (b) Find 0:= Uw, the angle between the given two vectors. 4) Let x < 0. Find the vector = < x, y, z>that is orthogonal to all three vectors = < 1,1, -2>, V = < -1,2,0> and W= < -1,0,1>. 5) Find a unit vector that is orthogonal to both = < 0,-1,-1> and < 1,0,-1 >.