What is the first step in the construction of a line perpendicular to and passing through an external point M? Assume that the construction uses only a compass and a straightedge. A.
Place the compass needle on M and, keeping the compass width the same, draw two arcs that intersect .

B.
Place the compass needle at any point on , and set the compass width to M.

C.
Draw a line from point M passing through , and mark the point of intersection.

D.
Place the compass needle at any two points on , and draw two arcs through M.

A.)lPace the compass needle on M and, keeping the compass width the same, draw two arcs that intersect

Step-by-step explanation:

In the construction of a line perpendicular to AB←→ and passing through an external point M the first step must be"Place the compass needle on M and, keeping the compass width the same, draw two arcs that intersect AB←→". After that you can draw arcs from intersection points (keeping the compass width same as before) to the opposite side of M, name it as N than use straightedge to draw line passes through M and n that would be perpendicular line to AB.