Question

suppose we wish to construct a line segment at point a which is perpendicular to segment bc. a correct first step would be to a place the compass point at a. b place the compass point at b. c place the compass point at c. d place the compass point at d.

Explanation:

Step1: Recall the construction of perpendicular line

To construct a perpendicular line at a point on a line segment, the first step is to use the compass. When constructing a perpendicular to segment \(BC\) at point \(A\), we need to start with the compass operations related to point \(A\).

Step2: Analyze each option

• Option A: Placing the compass point at \(A\) is a valid first - step. We can then adjust the compass width and draw arcs on either side of \(A\) on the line \(BC\).
• Option B: Placing the compass at \(B\) is not relevant for constructing a perpendicular at \(A\) directly. We are focused on the point \(A\) for this construction.
• Option C: Placing the compass at \(C\) is not relevant for constructing a perpendicular at \(A\) directly.
• Option D: Placing the compass at \(D\) (a random point on \(BC\) other than \(A\)) is not the correct first - step for constructing a perpendicular at \(A\).

Answer:

A. place the compass point at A.