Question

Joel is constructing a line perpendicular to BW←→ . He has already constructed three arcs as shown.

He moves his compass point to W to construct a fourth arc.

What must be true about the width of Joel’s compass opening before he draws the arc?

It must be the same as it was when constructing the arc above P.

It must be wider than it was when constructing the arc above P.

It must be narrower than it was when constructing the arc above P.

Answer 1

The answer is A, it must be the same as it was when constructing the arc above P.
The intersections of the arcs above and below the line are joined to produce the perpendicular bisector.

Answer 2

The correct answer is:

It must be the same as it was when constructing the arc above P.

Step-by-step explanation:

When constructing a perpendicular bisector of a line, we set the compass width to a little over half of the distance between the two points.

We construct an arc both above and below the line from the first point (B). Using the compass set at the same width, we construct an arc above and below the line from the second point (W). These will intersect the first two arcs and create the points to use for our bisector.

Lastly, we draw a segment through these points.

If the compass was not set to the same width, the arcs would not intersect and we would not construct our bisector.