Question

Vector addition using geometry is accomplished by putting the tail of one vector (in this case B⃗ ) on the tip of the other (A⃗ ) (Figure 1) and using the laws of plane geometry to find the length C, and angle ϕ, of the resultant (or sum) vector, C⃗ =A⃗ +B⃗ :

Answer 1

length of C will be found using pythagoras's theorum and rearranging for the thing you want. draw the vectors, complete them into a triangle and find the length of the side you want using:
hypotenuse^2 = side1^2 + side2^2

you can find the angle by using any trig function