必須英単語 perpendicular

perpendicular = at an angle of 90° to a horizontal line or surface 1:54 came straight at me. perpendicular (to this boat) bang, right there.

Why Riding a Jet Ski Can Be Dangerous

1:19 if you do end up getting caught in a rip current. stay clam and swim parallel to the shore. rip currents come perpendicular to the shore. 離岸流に流された時には、落ち着いて海岸線に平行になるように泳ぎましょう。離岸流は海岸線に対して直角（垂直）に流れてくるからです。

40 Strangers Form Chain to Rescue Swimmers on Lake Michigan