Question

standard: g.gsr.4.3 - dok1
which of these is the first step in constructing a line perpendicular to $overline{lm}$ through point $b$?
construct the midpoint of $overline{lm}$.
use a ruler to draw a line through point b that is perpendicular to $overline{lm}$.
place the compass on l and draw an arc that is more than halfway across $overline{lm}$.
place the compass on b and draw a single arc that intersects $overline{lm}$ twice.

Explanation:

To construct a perpendicular line from an external point (B) to a line ($\overline{LM}$), the first step is to place the compass on the external point (B) and draw an arc that intersects the given line ($\overline{LM}$) twice. This is a fundamental step in the geometric construction process for perpendicular lines from an external point.

Answer:

Place the compass on B and draw a single arc that intersects $\overline{LM}$ twice.