The angle between vertical and horizontal vector is 90 and cos 90 is 0
So R(resultant) = root( 7 square + 12 square)
= root (49 + 144 )
= root ( 193 )
We know root 196 is 14 soo 193 is nearly 14 but if they asked you can use a calculator, the answer is 13.8924439894
