Please choose the correct ending to complete the given sentence: Education and Communications: [header] How to construct a perpendicular line to a given line through point on the line [title] Line up the given line and the protractor. [step] Set the protractor's origin hole over the line's given point. Align the protractor so that its base line sits exactly over the given line.

Ending1: [substeps] The protractor should now look like a vertical graph that stays connected at a diagonal through fixed regions. Note: if the vertical axis of the target line is labeled as angle 1, this lines intersect as shown on the graph. Ending2: [title] Position the other end of the protractor over and over the line's hypotenuse (the line intersecting the hypotenuse pit). [step] Align the hypotenuse pit so that its base line sits exactly over the hypotenuse pit. Ending3: This is the node of the line, so point the protractor at it. Line up the marked line horizontally and curve to make it perpendicular. Ending4: [substeps] The origin hole is the small hole at the bottom-center of the protractor. The base line is the line on the bottom of the protractor marking 180/0 degrees.

Answer format: ending1/ending2/ending3/ending4