You are instructing a child to divide an A4 paper into 2 equal pieces as the above picture.
Is it correct to say
"fold the paper longways in half" (I don't want to fold it sideways)
"then rip it apart in half along the folded line" or "then rip it straight in half along the folded line"
"don't rip it apart from the folded line" (if I don't rip it along the folded line, then I might end up having 2 pieces that are not equal and stright)