Question

A draftsman made an incomplete design of a bridge. He has to construct the support BD which is perpendicular to the segment AC. He places the compass at B and draws two arcs at M and N, as shown.
PIC http://oi47.tinypic.com/imhxl4.jpg

ASNWERS BELOW.

Answer 1

Which statement best describes the next step of the construction?

Take the width of the compass equal to segment BM and draw an arc across AB and BC from point B.

Take the width of the compass equal to segment CD and draw an arc across MN and BC from point C.

Place the compass on point B and draw arcs across segments BA and BC.

Place the compass on point M and point N and draw arcs which intersect below the line segment AC.

Answer 2

I think the last one is correct. If you draw arcs from M and N below AC then they will intersect directly in the middle of the two spots. The place they intersect will be the mid point of AC which is where BD is. That's how I'd would think of it at least.

Answer 3

Oh ok,Thank you!