Alex wants to construct a line segment through R that makes the same angle with line segment QR as line segment PQ. The figure below shows a step to construct a congruent angle at R:

A line segment QR is drawn. PQ is a line segment that makes an obtuse angle of about 120 degrees with QR. An arc, indicating the measure of angle PQR, intersects PQ at S and QR at T. Another arc drawn from point R is a reflection of the first arc but of the same measure and intersects QR. A compass with its ends at points S and T is shown.

Which figure shows the next step to construct a congruent angle at R?

A line segment QR is drawn. PQ is a line segment that makes an obtuse angle of about 120 degrees with QR. An arc, indicating the measure of angle PQR, intersects PQ at S and QR at T. Another arc drawn from point R is a reflection of the first arc but of the same measure and intersects QR. A line segment RX is drawn that makes the same angle with QR as QP makes with QR. A straightedge is placed along the length of RX.
A line segment QR is drawn. PQ is a line segment that makes an obtuse angle of about 120 degrees with QR. An arc, indicating the measure of angle PQA line segment QR, is drawn. PQ is a line segment that makes an obtuse angle of about 120 degrees with QR. An arc, indicating the measure of angle PQR, intersects PQ at S and QR at T. Another arc drawn from point R is a reflection of the first arc but of the same measure and intersects QR. A straightedge is placed along arc ST.
A line segment QR is drawn. PQ is a line segment that makes an obtuse angle of about 120 degrees with QR. An arc, indicating the measure of angle PQR, intersects PQ at S and QR at T. Another arc drawn from point R is a reflection of the first arc but of the same measure and intersects QR. A compass is shown drawing a small arc to intersect the big arc near R.
A line segment QR is drawn. PQ is a line segment that makes an obtuse angle of about 120 degrees with QR. An arc, indicating the measure of angle PQR intersects PQ at S and QR at T. Another arc drawn from point R is a reflection of the first arc but of the same measure and intersects QR. A compass is shown drawing an arc between PQ and QR from point S.

1 answer

To construct a line segment through point R that makes the same angle with line segment QR as line segment PQ does, we need to complete the construction after drawing the arcs from point R. Here’s a breakdown of what’s already been done and what comes next:

  1. You have line segment QR and line segment PQ that create an obtuse angle (around 120 degrees).
  2. You’ve marked the intersections of the arcs from PQ and QR with points S and T.
  3. You’ve drawn another arc from point R that’s a reflection of the first arc, intersecting QR.

Now, the next step involves using the compass to ensure that the angle formed by the new segment RX at point R matches the angle formed by PQ and QR.

Among the options, the correct one for the next step would be:

A line segment QR is drawn. PQ is a line segment that makes an obtuse angle of about 120 degrees with QR. An arc, indicating the measure of angle PQR, intersects PQ at S and QR at T. Another arc drawn from point R is a reflection of the first arc but of the same measure and intersects QR. A compass is shown drawing a small arc to intersect the big arc near R.

This option describes the necessary step where you use the compass to create a small arc that helps mark the angle at point R, allowing you to construct line segment RX to ensure that it matches the angle formed by PQ at point P.